I agree totally here. Rap sure isn't my thing, but the fact is (as in all genres) that their's the true artists, and the commercialy immitators. I think that it's easier to make a "fake" rapper than it is a rock band, but Techno is even easier than rap to fake. SO...
Lets look at this like the resonable human beings and artists I hope we all are:
1). It does take talant to Rap- lyrics are lyrics folks
2). Don't confuse the commercialized crap that's put out en masse with the real thing. If you think all rap is the sterio typical "gansta" rap, then you despeately need to check out some Public Enemy and KRS-1. Most old school rap is at the least very clever stuff- even if it's a song about big butts.
3). Many rappers are musicians. Turn Tables is an insturment. If you don't beleive me, try putting a needle down on a record in exactly the right spot to make a specific sound, or to mix two records together- LIVE. Also, you do find traditional "rock" instruments being played in Rap, take the Bestie Boys or Jurassic Five for instance.
4). MTV does shove good music in with the duldrums of it's average broadcast day. I don't care what any of you think, Incubus is an awesome band (though I pray they don't sell out on me), and I have seen them live so I know they're better than you hear on the radio.

So what do I think are the important factors?
Live performance, is absolutely critical in my mind. As a musician I feel it's all about the live show (though I love to record). You have to be able to create music that's interesting and original, and you need to be able to pull it off on stage in front of an audience (which goes back to point one).

Remember folks, this is art.