Why do people say Cena is not overrated, when he clearly is?

I've never heard of a person who holds a title for almost an entire year, gets beat up almost the entire match and somehow overcomes the odds and wins, rarely lets anyone hold the title longer than him, is always mentioned when someone talks about the WWE, and finsher that consists of a Fireman's Carry not being overrated. If you don't think Cena's overrated please do tell me why he's not.