#4 Unparalleled Loyalty to WWE
One might wonder, why of all people John Cena who is given everything a WWE superstar can aspire, to have any problems with the management. However, the cases of the people who were in his shoes earlier speak otherwise. Hulk Hogan was the face of the WWF in the 80's, he fled to WCW as soon as he saw an opportunity there. He also criticized the WWE on certain occasions back when it wasn't the solo largest wrestling promotion. Bret Hart, though being given the worst possible farewell also signed a contract with WCW and has criticized WWE on several occasions (I in no way intend to say he shouldn't have). Now coming to megastars who had problems when there was no WCW, Austin left the company unceremoniously in 2003 citing creative differences and refusing to be the first guy to put Brock Lesnar over. The Rock left the WWE when he was just beginning to use his fame to put younger stars over. Even Ric Flair who was never exactly the face of WWE, fled to TNA after the company gave him one of the best retirements possible.
Unlike all of them, John has always stood by Vince's company in the good, bad and the ugly. He has never in his life said anything negative about the company publicly. Even when his time as face of the company got over, he selflessly put over his successor Roman Reigns and also several other modern wrestlers for that matter. Even, now when his movie career is as enviable and self-reliant as it has ever been, John still stands by the company.
Some may argue that he is still keeping WWE as a fallback option, however with his position, he could easily negotiate a sporadic appearance contract similar to Brock Lesnar or The Undertaker. However, whenever he returns, he competes as a regular wrestler, on Raw/Smackdown and even on house shows. There hasn't been a 'face of the company' in WWE who has gone full cycle on his role, i.e. Rising to the top, Tenaciously performing at a top level for over a decade, and when the time comes, passing the torch; as ostensibly as John has.