Yeah, whether or not it's truly generational, the "stigma" of oral sex is long gone, I would say due to a host of factors (I include previous posters' reasons):

1. The liberalization of sex more generally
2. The much lower rates of infection for oral which is still "serious" sexual activity
3. The proliferation of hardcore porn in conjunction with "informational" aspects of the internet/sex columns ("Savage Love", Craigslist) makes oral practically as benign as hand-holding by comparison
4. Cleaner bodies, less physical labor

I would like to add a further aspect that has more to do with cunnilingus rather than blowjobs: an experienced young male who feels compelled to give his partner pleasure is no doubt flummoxed to a certain degree by the female anatomy: not only are things less straightforward than for men, but there are wide-ranging differences in what works for each woman, and it takes time to learn how to figure this out as well as develop the maturity to talk to one's partner about what she wants. Far and away the easiest approach (which also garners extra kudos) is to just get down there and paint with the broad brush of one's tongue--it's hard to miss the "right button(s)" that way, and it also speeds things along (which, let's face it, is perhaps too often the guy's goal in most cases anyway).

To this end, "kids today" I think despite getting some extremely troubling messages about sex in media of all sorts, nonetheless strive for "good sex," not just sex as a vital part of growing up.