I'm Begging You!!! Can somebody please explain this whole "mumble" rap thing? What's the appeal???

I don't get it. I really don't.  How is this so-called genre even considered music?  Call me old fashioned but isn't hip hop and rap about the LYRICS????  

It seems everywhere you turn there's a new "hot", young rapper on the scene hitting it big with some unintelligible nonsense set over a beat and the crazy part about it is that people seem to like it because these talent-less fools are making tons and tons of cash.  I mean really, how much talent is actually required to sip on a cup of "lean" (don't even get me started on this whole issue) and slur some words into a mic that probably don't even mean anything anyway?  Lyrics are what rap is all about.  If you can't understand any of the lyrics then what's the point?  All joking aside though, I really would love for someone to explain the appeal to me.  I'm always willing to hear the other side.  Even if I do think Biggie would roll over in his grave if he heard some of this stuff!