50 Cent built his entire career doing this, i.e. calling out rappers. Not saying he's just as skilled, but this is not the least bit innovative or interesting, even from a marketing perspective--it's been done a bunch of times. Does it work? Of course. Is it genius? Not really. I've heard people ranting about Kendrick for a long time and I still don't get it, I guess I need to listen to more before I draw any conclusions.
Same people who tell me Kendrick is good say Drake is good, so obviously it's hard to take them seriously.