Because he buries other wrestlers! Once a wrestler starts to gain some momentum they are thrown to SuperCena and that is the end for them. No new talent is allowed to get over because he won't let them get over.
He almost NEVER loses clean, his gimmick is stale, he really can't wrestle and normally needs to be carried by better in ring workers, the fact that the WWE has to remind everyone he is a 15 time world champ, he did that in 10 years so that means his title reigns are very short. But the main reason really is he buries talent. Look at Bray Wyatt and Rusev those guys had momentum and now are obsolete because of Cena and his backstage politics.
Cena will probably get the title at the next PPV and Seth Rollins will become obscure.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.