As a Yankee fan, I can't defend Jeter not going, but he's entitled to do what he wants. A lot of players decline to go, except this year he was the glaring one of four Yankees not going. ARod had knee surgery the day before and Mo is dealing with a nagging injury. CC made plans after he didn't make the team and was scheduled to pitch on Sunday. Even if he got selected, he couldn't play. Why sit around for the chance to go stand around in Arizona?
As for Jeter, whatever. I'm sure he regrets it now because of all the fuss made of it, but he was just getting over an injury and had to deal with all the publicity of 3000. Four full days off sounds a whole lot better than traveling to Arizona to play 3 innings. I personally didn't care that he wasn't there, and I don't know why so many non-Yankee fans took offense to it. Sure, he got voted in unjustifiably, but he didn't ask for it, I don't recall him campaigning for votes.
Didn't Pedro Martinez skip it multiple times?
And I do believe All-Star selections are still important. There isn't such a big difference between an 8-time All-Star and a 6-time one. But there is a difference between those two and a 14-time or 2-time one. And bringing together the best of the best usually translates to more interest, which is always a good thing for any sport.