Well, they want to promote Cena as the future face of the company, so it doesn't make much sense for said future face to be laid out like a punk on a major network show that's supposed to draw in new fans. You have to remember that SNME isn't treated like a normal WWE show. It's 1/2 normal show, 1/2 promotional, so that's why you get Cena standing tall at the end.
The majority of Cena's matches involve him selling. Don't bring up the spear on SNME either, because he can't sell the move like death since he has to do the super FU to close the show. Blame the booking for that, not Cena.
Angle does nothing to set up the ankle lock, either, so what's your point? Should he set it up? Sure. But the only guy who really set's up his submissions is Benoit.