The problem with hip hop and rap isn't that they're bad genres of music (they're not), but rather that the most visible examples of the genres suck. Look at modern popular rap--many of the lyrics are chauvinistic, demeaning, mindless, generally unsavory, etc. However, beneath that crust of shit, there are plenty of artists who legitimately have something to say and can do so with skill and musicality. Like the OP points out, Atmosphere is a particularly good example (check out Yesterday or Guarantees if you want some proof that rap can be intelligent), and I would throw Sage Francis out there as another damn good example of someone who can handle a mic and can use it for something intelligent (see Gunz Yo, Slow Down Gandhi, The Best Of Times, or Conspiracy To Riot)--but be warned that he can be VERY political. So generally speaking, I think that hip hop (and more specifically rap) is a medium with a lot of potential that's getting wasted on Lil' Wayne and the like. There's some really, really cool stuff that nobody notices underneath the piles of drivel.
Finally, my advice to those that don't like rap: please stop just shitting on it without a second thought. Hip hop is a genre as diverse as rock, so it's difficult to definitively say "This is bad" unless you put in a lot of listening time. Besides, even if it's not for you, that doesn't make it all automatically bad--I'm not a particular fan of metal (much of it strikes me as pointlessly, boringly aggressive), but that does not mean that all metal is bad just because I don't like it. Please, extend the same sort of courtesy to hip hop.
