Something can still be great and be overrated, as people are putting 100xs too much on it. Kind of like Nirvana, they are a great band, they are still overrated. The verse is overrated in the sense that people are calling it "the best verse of the decade" and a "game changer" on twitter and the such. Like I said it sounds like Kendrick listened to some Canibus, put on his angry voice, and then there you have it. It's a great verse and honestly it's nothing much more than that.
Lets be honest if that verse was spit in 1996 when rappers weren't all on some "We Are the World" lets be best friends and work together and get money type shit it would hardly make a ripple. Take that for what you want for where we are at with rap music in 2013.