I just get tired of the US supporting guys like Mubarak because "the opposition would be worse." and "he's our friend". It just seems like at some point these guys all get overthrown and we're stuck with someone worse and a country full of people who hate the USA because we supported the last guy.
Sure, but that would have happened anyway. In the interim, we had 30 years of stability for American interests in Egypt. Might the next Egyptian regime hate America for supporting Mubarak for 30 years (and Sadat for 10 years before that)? Sure. But from 1970-2010, Egypt didn't go to war against any of its neighbors, the Suez Canal was kept open to international trade, and we had one less extremist nation on our side.
If, let's say, after Sadat was assassinated, America pulled back all support for Mubarak and insisted on free elections in 1981. Chances are that if Mubarak didn't take over, someone else in the military would have. The other likely alternative was that an armed militant group would have taken over. Egypt simply didn't, and in my opinion, still does not, have the political structure in place to support a bona fide democratic system.
So we'd have a military dictatorship or a religious theocracy. Even if America pulled all support, Egypt would have ended up following the model of other military dictatorships in the region, like Libya and Syria, or would have become a religious dictatorship, much like Iran had become at around the same time (but Sunni, rather than Shia).
Iran became a theocracy in the late 1970's and it has not moderated in the 40 years since. Libya became a brutal military dictatorship -- not supported by America -- in 1969 and has not moderated since then. There's no reason to think that if America had withdrawn support from Mubarak in 1981, that we'd see a liberal democracy flourishing in Egypt today. All the evidence, from looking at the behavior of similarly situated nations, is that Egypt would be a repressive regime with or without American aid.
What we got from the last 40 years, however, if an Egypt that did not start wars against its neighbors and that did provide an ally for Western interests. It's not a huge benefit, but it probably is our best-case scenario.
And if Mubarak is replaced by another military dictator or by religious extremists, we're no worse off than we would have been if the same thing happened in 1981 -- on in 1952 when Nasser first instituted a military dictatorship in Egypy, to which Mubarak is simply the successor.
Realpolitik is ugly, and it's messy, and it is unsavory, but it still produces results that are better than isolationism, which is really the only practical alternative here.