In addition, the severity of these occurrences can be huge. When you can afford to hold, crashes like the last one are only lost opportunities, not actual losses -- but when you need to have Bitcoin working actively for you, a price drop like that can be catastrophic.
In spite of your cherry picking, the graphs you have displayed don't show bitcoin to be the catastrophe you are desperately trying to prove. Quite the reverse in fact. There is far more green than red on those charts meaning that most of the time it is profitable to use bitcoins.
You don't have to take my word for it. The
MtGox site allows you to download the raw data for any time period which I have done for your second chart and summarized in the table below. I have considered two scenarios concerning a person who's bitcoin takings is valued at $100.00 per day (the third column shows how many coins he would have collected at the weighted mean price).
In the first scenario, the person sells those bitcoins the next day for whatever the weighted mean price is (column 2). Column 4 shows how much profit (or loss) he would have made due to the price variations. If you total that column, you will find he still comes out $279.53 ahead compared to what he would have done if he had only dealt with fiat currency. This is in spite of the heavy falls in bitcoin prices recently (and they are recovering).
In the second scenario, the person holds on to the bitcoins and doesn't sell them at all. The sixth column shows the value of his bitcoin holdings for each day this year. By 28 April, the value of his holdings would have been $53,825.85 which is not bad considering that $100 per day for 119 days only totals $11,900.
BTW it is not correct to say that bitcoin prices couldn't have crashed prior to April 2011. As the
Bitcoin Chart for Jan to April 2011 shows, the price of bitcoins doubled in the first week of February. Just because the price of bitcoins at that time was in cents rather than dollars doesn't mean that there wasn't a profit to be had.
[table=head]DATE|PRICE|COINS|DAILY PROFIT|CUMULATIVE|VALUE
2012-12-31|$13.48|7.41840|$0.00|7.41840|$100.00
2013-01-01|$13.34|7.49625|-$1.04|14.91465|$198.96
2013-01-02|$13.31|7.51315|-$0.22|22.42780|$298.51
2013-01-03|$13.36|7.48503|$0.38|29.91283|$399.64
2013-01-04|$13.42|7.45156|$0.45|37.36439|$501.43
2013-01-05|$13.45|7.43494|$0.22|44.79934|$602.55
2013-01-06|$13.46|7.42942|$0.07|52.22876|$703.00
2013-01-07|$13.51|7.40192|$0.37|59.63068|$805.61
2013-01-08|$13.72|7.28863|$1.55|66.91931|$918.13
2013-01-09|$13.74|7.27802|$0.15|74.19733|$1,019.47
2013-01-10|$14.05|7.11744|$2.26|81.31477|$1,142.47
2013-01-11|$14.11|7.08717|$0.43|88.40194|$1,247.35
2013-01-12|$14.17|7.05716|$0.43|95.45910|$1,352.66
2013-01-13|$14.11|7.08717|-$0.42|102.54628|$1,446.93
2013-01-14|$14.26|7.01262|$1.06|109.55890|$1,562.31
2013-01-15|$14.20|7.04225|-$0.42|116.60115|$1,655.74
2013-01-16|$14.52|6.88705|$2.25|123.48821|$1,793.05
2013-01-17|$15.17|6.59196|$4.48|130.08016|$1,973.32
2013-01-18|$15.68|6.37755|$3.36|136.45771|$2,139.66
2013-01-19|$15.46|6.46831|-$1.40|142.92602|$2,209.64
2013-01-20|$15.72|6.36132|$1.68|149.28734|$2,346.80
2013-01-21|$16.38|6.10501|$4.20|155.39235|$2,545.33
2013-01-22|$17.15|5.83090|$4.70|161.22325|$2,764.98
2013-01-23|$17.22|5.80720|$0.41|167.03045|$2,876.26
2013-01-24|$17.75|5.63380|$3.08|172.66426|$3,064.79
2013-01-25|$16.66|6.00240|-$6.14|178.66666|$2,976.59
2013-01-26|$17.15|5.83090|$2.94|184.49756|$3,164.13
2013-01-27|$17.65|5.66572|$2.92|190.16328|$3,356.38
2013-01-28|$18.34|5.45256|$3.91|195.61585|$3,587.59
2013-01-29|$19.17|5.21648|$4.53|200.83233|$3,849.96
2013-01-30|$19.48|5.13347|$1.62|205.96580|$4,012.21
2013-01-31|$20.58|4.85909|$5.65|210.82489|$4,338.78
2013-02-01|$20.73|4.82393|$0.73|215.64881|$4,470.40
2013-02-02|$19.47|5.13611|-$6.08|220.78492|$4,298.68
2013-02-03|$20.26|4.93583|$4.06|225.72075|$4,573.10
2013-02-04|$20.42|4.89716|$0.79|230.61791|$4,709.22
2013-02-05|$20.57|4.86145|$0.73|235.47936|$4,843.81
2013-02-06|$21.09|4.74158|$2.53|240.22095|$5,066.26
2013-02-07|$21.61|4.62749|$2.47|244.84843|$5,291.17
2013-02-08|$22.42|4.46030|$3.75|249.30874|$5,589.50
2013-02-09|$23.24|4.30293|$3.66|253.61166|$5,893.94
2013-02-10|$23.42|4.26985|$0.77|257.88152|$6,039.59
2013-02-11|$24.13|4.14422|$3.03|262.02574|$6,322.68
2013-02-12|$25.09|3.98565|$3.98|266.01139|$6,674.23
2013-02-13|$25.48|3.92465|$1.55|269.93604|$6,877.97
2013-02-14|$25.46|3.92773|-$0.08|273.86377|$6,972.57
2013-02-15|$26.99|3.70508|$6.01|277.56884|$7,491.58
2013-02-16|$27.16|3.68189|$0.63|281.25073|$7,638.77
2013-02-17|$26.40|3.78788|-$2.80|285.03860|$7,525.02
2013-02-18|$26.76|3.73692|$1.36|288.77553|$7,727.63
2013-02-19|$28.19|3.54736|$5.34|292.32288|$8,240.58
2013-02-20|$29.47|3.39328|$4.54|295.71616|$8,714.76
2013-02-21|$29.68|3.36927|$0.71|299.08544|$8,876.86
2013-02-22|$30.46|3.28299|$2.63|302.36843|$9,210.14
2013-02-23|$29.05|3.44234|-$4.63|305.81077|$8,883.80
2013-02-24|$29.78|3.35796|$2.51|309.16873|$9,207.04
2013-02-25|$30.07|3.32557|$0.97|312.49430|$9,396.70
2013-02-26|$31.01|3.22477|$3.13|315.71907|$9,790.45
2013-02-27|$31.22|3.20307|$0.68|318.92214|$9,956.75
2013-02-28|$32.69|3.05904|$4.71|321.98118|$10,525.56
2013-03-01|$34.24|2.92056|$4.74|324.90174|$11,124.64
2013-03-02|$33.87|2.95247|-$1.08|327.85421|$11,104.42
2013-03-03|$34.13|2.92997|$0.77|330.78418|$11,289.66
2013-03-04|$35.47|2.81928|$3.93|333.60347|$11,832.91
2013-03-05|$39.35|2.54130|$10.94|336.14476|$13,227.30
2013-03-06|$45.18|2.21337|$14.82|338.35813|$15,287.02
2013-03-07|$40.93|2.44320|-$9.41|340.80133|$13,949.00
2013-03-08|$43.16|2.31696|$5.45|343.11829|$14,808.99
2013-03-09|$45.44|2.20070|$5.28|345.31899|$15,691.30
2013-03-10|$46.84|2.13493|$3.08|347.45392|$16,274.74
2013-03-11|$47.62|2.09996|$1.67|349.55388|$16,645.76
2013-03-12|$43.70|2.28833|-$8.23|351.84221|$15,375.50
2013-03-13|$46.41|2.15471|$6.20|353.99692|$16,429.00
2013-03-14|$47.31|2.11372|$1.94|356.11063|$16,847.59
2013-03-15|$47.03|2.12630|-$0.59|358.23694|$16,847.88
2013-03-16|$46.86|2.13402|-$0.36|360.37095|$16,886.98
2013-03-17|$47.40|2.10970|$1.15|362.48066|$17,181.58
2013-03-18|$48.98|2.04165|$3.33|364.52231|$17,854.30
2013-03-19|$55.39|1.80538|$13.09|366.32769|$20,290.89
2013-03-20|$62.02|1.61238|$11.97|367.94007|$22,819.64
2013-03-21|$69.07|1.44781|$11.37|369.38788|$25,513.62
2013-03-22|$70.65|1.41543|$2.29|370.80330|$26,197.25
2013-03-23|$62.67|1.59566|-$11.30|372.39896|$23,338.24
2013-03-24|$68.92|1.45096|$9.97|373.84992|$25,765.74
2013-03-25|$74.25|1.34680|$7.73|375.19672|$27,858.36
2013-03-26|$77.25|1.29450|$4.04|376.49122|$29,083.95
2013-03-27|$84.87|1.17827|$9.86|377.66949|$32,052.81
2013-03-28|$87.41|1.14403|$2.99|378.81353|$33,112.09
2013-03-29|$88.78|1.12638|$1.57|379.93991|$33,731.07
2013-03-30|$91.72|1.09027|$3.31|381.03018|$34,948.09
2013-03-31|$92.70|1.07875|$1.07|382.10893|$35,421.50
2013-04-01|$100.04|0.99960|$7.92|383.10853|$38,326.18
2013-04-02|$107.61|0.92928|$7.57|384.03781|$41,326.31
2013-04-03|$127.89|0.78192|$18.85|384.81973|$49,214.60
2013-04-04|$131.61|0.75982|$2.91|385.57956|$50,746.13
2013-04-05|$139.22|0.71829|$5.78|386.29784|$53,780.39
2013-04-06|$142.16|0.70343|$2.11|387.00128|$55,016.10
2013-04-07|$154.26|0.64826|$8.51|387.64953|$59,798.82
2013-04-08|$181.49|0.55099|$17.65|388.20053|$70,454.51
2013-04-09|$214.67|0.46583|$18.28|388.66636|$83,435.01
2013-04-10|$184.65|0.54157|-$13.98|389.20792|$71,867.24
2013-04-11|$158.93|0.62921|-$13.93|389.83713|$61,956.82
2013-04-12|$85.57|1.16863|-$46.16|391.00576|$33,458.36
2013-04-13|$110.21|0.90736|$28.80|391.91312|$43,192.75
2013-04-14|$97.41|1.02659|-$11.61|392.93971|$38,276.26
2013-04-15|$87.07|1.14850|-$10.61|394.08821|$34,313.26
2013-04-16|$65.33|1.53069|-$24.97|395.61890|$25,845.78
2013-04-17|$85.27|1.17275|$30.52|396.79165|$33,834.42
2013-04-18|$97.38|1.02690|$14.20|397.81855|$38,739.57
2013-04-19|$119.43|0.83731|$22.64|398.65586|$47,611.47
2013-04-20|$124.02|0.80632|$3.84|399.46219|$49,541.30
2013-04-21|$121.50|0.82305|-$2.03|400.28523|$48,634.66
2013-04-22|$123.23|0.81149|$1.42|401.09672|$49,427.15
2013-04-23|$134.63|0.74278|$9.25|401.83950|$54,099.65
2013-04-24|$152.07|0.65759|$12.95|402.49709|$61,207.73
2013-04-25|$143.07|0.69896|-$5.92|403.19605|$57,685.26
2013-04-26|$132.25|0.75614|-$7.56|403.95219|$53,422.68
2013-04-27|$131.18|0.76231|-$0.81|404.71450|$53,090.45
2013-04-28|$132.75|0.75330|$1.20|405.46780|$53,825.85[/table]