Critics of Rebirth say that Lil Wayne is a rapper, not a rock star, and that he should stick to rapping. It's funny, because not giving a fuck what critics are saying is one of the things that makes Lil Wayne more of a rock star than most guitar-slinging musicians these days. He may not have the guitar skills, and his Autotune-heavy, hybrid version rock/rap is never going to sit well with some people who are still waiting for the reinvention of blues, but Lil Wayne brought an attitude to Rebirth that's been missing in mainstream rock for years.
Think about how many real rock stars we have in popular music these days, then think about why that number is so low. Once rockers get popular, they usually end up getting complacent and safe. With Rebirth, Tunechi took a huge risk simply because he wanted to, and when you revisit tracks like "Ground Zero," "Drop The World," and "Knockout," you might even realize that he stumbled upon some great moments while he did it.