I agree that the new SF Federal Building is really hideous looking, but it has some state of the art sustainability features that far surpass the good old days. Could this have been an attractive building with those same features? Sure, but the trend followers want it this way - ugly.
FvB is on the right track, I think. It is not the style itself, but the interaction between the style, the culture and the political system, that created the problem.
Perhaps modernism is so successful because it's so hard to do well. It's a classic academic fuck-you: create an unsolvable problem and then solve it. Can you build a beautiful building out of flat, bare concrete? I can. Guess my SAT must be higher than yours. Pity about that, poor chap.
It's pretty easy to see how this essentially repellent attitude can thrive in a New Class world, where academic accomplishment is the only legitimate form of social status. It's also easy to see how the emperor's new clothes syndrome developed, and so many second-rate buildings, in which the subtle elegance was so subtle as to be nonexistent, got built.
Innovative architecture doesn't have to mean ugly architecture - just as innovative furniture doesn't (always) mean ugly furniture. But as long as architectural decisionmakers are juries and committees rather than eccentric, Randish corporate tycoons, Dilbert is here to stay. Playing by the New Class rules gives us New Class buildings - the architecture we deserve.
An extreme theory, but after spending a lot of time hanging around academia, I'm inclined to agree.