How? I can see how you might see that if you look at a label like YMCMB that attempts to take on pretty much every trend ever but look at the current crop of acts that are buzzing at the moment and you'll see how diverse their sounds are.
Kendrick
ASAP
Danny Brown
OFWGKTA
Raider Klan
Pro Era
Action Bronson
None of these dudes sound even remotely alike with the possible exception of Asap and Raider, but even then Raider Klan are much more lo-fi and Rocky has made a different sound for himself with the album. And it's not like they're the only rappers around. Lots of older artists like Nas are still around making their own style of music. Dudes like Curren$y stay in a unique chilled out lane. International acts like M.I.A. take Hip-Hop and combine it with pretty much everything.
I think it's a great time to be a fan of music. No matter how much shyt I might not like, it's pretty easy to find something I do. shyt, I was browsing shyt on Bandcamp the other day and I found some kid called Haleek Maul who makes some of the craziest shyt I've heard in a little while.

It's a good time breh. Truly the based god has blessed us