I don't find it alarming that they weren't involved. I thought briefly they might with Bono being a part time resident of NYC but, I don't have any ill feelings toward the band for not being involved. It isn't necessary for them to jump to the aid of every catastrophe in the world. I think the Jersey Shore had it's reps musically with Bruce and JBJ and quite honestly with a full line up like this:
Bon Jovi, Eric Clapton, Dave Grohl, Billy Joel, Alicia Keys, Chris Martin, The Rolling Stones, Bruce Springsteen & the E Street Band, Eddie Vedder, Roger Waters, Kanye West, The Who and Paul McCartney.
U2 wasn't really all that missed.