That aside, even if we could get a handle on the number of rapists, knowing that percentage of the male population isn't all that useful. The author seems keen on identifying rapists when the goal, and I know this sounds pedantic, is to avoid getting raped, not simply identifying rapists. Now, before anybody jumps my ass about this, hear me out.
Obviously if the article was about the odds of being raped by a stranger on the bus, she would be really wrong.
The reality is that her boyfriend or husband is far, far more dangerous to her statistically than Schrodinger's Rapist. Given no other factors, an intoxicated man is twice the risk of a sober one. A private setting is about 6X as dangerous as a public one. An intimate partner is 3.5X as likely as a stranger to commit the rape, and the pool of strangers is probably 100X bigger than the pool of intimate partners.
Talking to a sober stranger on a bus, even an obnoxious one, is far, far less dangerous than being at home with your drunk boyfriend.
No one has argued otherwise. A few points:
1) The odds of a random man on the bus raping a woman is very low, but she's not talking about all men. She's discussing a subset of men who first try to talk to women, then ignore women's wishes to be left alone, then follow them home or wait for them at bus stops.
What percentage of men who behave thusly will commit sexual crimes? I'm not aware of any stats that give us an indication, but surely you can see why a woman would be afraid of such a person.
The reluctance to engage strange men on the bus is part "they might be rapists," part, "they might follow me around and really scare me," and part, "I just don't want to tell this obnoxious ass to leave me alone over and over." The "Schrodinger's Rapist" allusion was meant to illustrate the worst case scenario. Because there are no reliable stats for that (riding the same bus for 6 months and following a woman home might be sufficient to say that the woman "knew" her assailant for the purposes of the stats) she just went for a broad number that is deeply flawed, but actually conservative. It's not conservative with respect to "strangers on a bus" but it is very much so with respect to men in general.
2) Even if the odds are very low, women should not be placed in a position of having to guess, "is this my worst fear coming true?" Much of the article explains what behavior terrifies them.
Not that many people get killed by bears, but if I'm hiking in the woods and see a grizzly 30ft away, my reaction won't be, "likely he won't devour me." I'll be scared until I'm safe.
If men can avoid causing that reaction in women, they should. She's explaining how to do so.
3) People are consistently failing to consider the severity of the prescribed action when guaging the reasonableness of the article.
By analogy: Person A lives on the 40th floor of a high-rise apartment building. She has a balcony. Her odds of falling to her death are very, very low. Nevertheless, she requested that guard rail be built and that maintenance people test its quality twice a year.
Is this an irrational stance? Her odds of death are very low.
Similarly, if the OP was demanding that women hire body guards or never leave home alone, it would be an irrational stance. She's merely asking that men respect her desire to be left alone, this is very reasonable and proportional to the threat involved.