I know you're not defending this booking--you're just stating the obvious--but what the fuck is the point of "protecting" Cena in the ridiculously overpowered state he is currently in? Wouldn't having him actually lose cleanly once in a while actually help his underdog schtick and get people to care about his matches more? This is doing the exact opposite; it's making the heels the underdogs in essentially every match he's in, which seems insanely counter-intuitive.
Vince should be protecting wrestlers that he is trying to establish as a main-event-level talent, not ones that are already astronomically over. Del Rio is a perfect example of this. He shouldn't be losing clean to every face on the roster. I'm not saying he has to make all of the faces tap, but at least let us think it's possible. As-is, no one thinks Del Rio would beat Cena one-on-one. Same goes for Miz, R-Truth, Barret, Rhodes, Ziggler, Swagger etc.. None of these guys, despite all of them getting/having gotten big pushes, seem like any real threat to the likes of Cena/Orton/Punk (it sucks to have to put Punk here, but it's true :S).
The only heel in recent memory to beat a face clean is Mark Henry, and holy shit, it worked! People care about Mark Henry! Now "marks" will perceive most of the roster as underdogs against Henry, and whoever on Smackdown finally beats him--assuming it's not fucking Orton--will get a huge amount of respect and will essentially be insta-pushed. Henry won't lose any credibility either, assuming that he's not booked like garbage after losing the title. We'll just have two more legit main eventers, instead of an overabundance of former champion mid-card jobbers.
For the record, I'm aware that most of this is common sense and that I'm preaching to the choir. But you just gotta sometimes, y'know?
Also, I really shouldn't have posted such a long rant at the very tail end of this thread. Don't be surprised/offended if I copy this into the November thread. I really want to foster some actual discussion about this topic, re: what is the purpose of "protecting" someone, and how talent should be established properly vs. how it's currently being done.