I hear alot of WWE fans say that John Cena is overrated, choking out new talent using corny gimmicks for children and that's more than enough reason to hate him. While this is true for him in modern WWE, it was not always so.
John Cena was a jobber in his early career once upon a time. He didn't intend on being famous. He only wrestled to push other wrestlers. It was only when the fans took an interest in him that WWE made the decision to push him. Because of this, John Cena was born and he won match after match, title after title, etc. Originally, he was geared to older audiences when he adopted the vulgar rap battle and later the soldier gimmick.
Now does he deserve all of the fame and championships? Yes. John Cena is main event material because he's a great entertainer in the ring and on the mic. He has an array of simple but powerfully devastating moves such as the FU and the submission STFU. He knows how to build up fierce emotional anticipation especially when he wrestled with the Undertaker in 2006. He was agile, aggressive, and about the same level of competition as the Undertaker. He knows how to build momentum when wrestling. He's also humorous in his promos. What the Undertaker and John Cena have in common is that both have faced popular superstars which contributed to the success of their careers.
His golden age began in the ruthless aggression era as he was somewhat equally balanced compared to other popular superstars. Do i believe he's hugely overrated now? Yes. The arrival of the PG era has pushed him unnecessarily and made him appeal to family friendly audiences. WWE simply pushed him to the point where he became the backbone. I would not blame John Cena, i would blame the PG era and WWE's putting him on the spotlight far too often.