When I talk to 16-21 year olds about U2, the responses I get from the musically aware ones are: "They were really cool up to the late 90's, but from Beautiful Day onwards they've just sucked a big one".
The irony here is that by targeting the young generation with songs like Vertigo, BD, GOYB and Crazy, U2 have actually become desperately unhip in the eyes of the kids. I heard the phrase "dad cock rock" a couple of times.
So yeah, they have totally lost touch with the young generation. Most couldn't care less about them (or don't have a clue who they are other than they're an old rock band from England or somewhere) and the rest think they've become desperately lame. As others have said here, they should just stop worrying about appealing to the kids and make innovative, interesting music.