Not from 2005-2010 and probably not entirely his fault, but he's had a pretty negative effect on Zack Ryder, the whole Wyatt family, and Rusev.
Has more to do with the booking than anything, though.
Yeah, that's not really him. Vince was never going to push Ryder and was the dude who broke up the Wyatt Fam.
Vince also wants to break Lana off from Rusev, so Rusev's de-push was on the way. Plus, Rusev fits the "foreign monster challenges top patriotic babyface" formula that Vince loves and has returned to many times over the years.
Cena's admitted that he should have pushed more for the Nexus to win at key points in that feud.
My point is, however, that Cena hasn't buried anyone. From reports, he's a company man that does whatever they tell him. It's only in recent years that he has become more proactive in giving fresher dudes competitive matches to elevate them, and in fact even before that, he was the most giving main eventer the WWE has ever had except for The Rock. Cena's lost to RVD, Bryan, and Punk cleanly in order to try and elevate them and then went down a level to try and put guys over via the U.S. Championship open challenges, which is an angle that is likely ending in less than a week with Cena putting Owens over cleanly. Did Hogan ever do that much for that many people during his main run? Did Austin? Did Bruno?
No. Cena should get way more credit for being willing to drop falls, especially cleanly, than he does. And of course, why does it mean so much for Cena to drop a fall cleanly now? Because he almost never lost for years and years!