I reserve the right to change my opinions at any time when I feel something warrants it, kind of like how I think the New Day is the most interesting thing on the show for about the last month or so, after being very meh before that. That said, at the moment, you are correct that right now, I'm certainly not a Cena fan at all.
I'm not debating Cena(the man) at all, I know he is arguably as valuable as anyone in WWE history and is the well established face of the company. My problems are with the booking and Cena(the character) both of which are awful. Cena has this whole hustle, loyalty and respect thing, but his actions are almost the exact opposite. Don't get me wrong, other guys are disrespectful, but they aren't shoved down our throats as this honorable, holier-than-thou hero like Cena is. It makes Cena come off as a gigantic hypocrite and crybaby all the time.
I mean, what part of being respectful is photoshopping dresses onto the Wyatt family and making fat jokes? Or jumping Rusev after a match and then knocking him out, only to revive him, so he can hurt him more? How about him having the the US open challenge because he wants somebody to step up and beat him, and then when someone does, he throws a hissy fit and says he isn't a real man. Those are just examples in the past year. Now if Rollins were doing those things it would be ok, because he is supposed to be a hypocrite and a jerk.
Also, while Hogan and Michaels likely wouldn't have ever lost to a guy in his debut, when they lost it mattered. Cena lost to Punk, then got seemingly infinite rematches for no reason, while the announce team called Punk a coward for not wanting to grant Cena a dozen rematches. Brock was the same thing, so was Rusev, and now it looks like Owens will be the same. If Cena gets his win back, then who cares that he lost in the first place. I mean, Hogan didn't get a rematch against Warrior, Michaels didn't get a rematch against Austin.
ETA: If all of this leads to Cena actually changing a little because he is worried he isn't the guy he once was, and that is why he is acting this way and hanging out in the midcard, where it is supposed to be easier, rather than challenging guys like Reigns and eventually Lesnar for a shot at the World Title, that would be amazing storytelling.