Because Ryback is made to look strong, they wanted him to look unbeatable and look like Punk was not able to stop him at all, that's why he doesn't sell.
This PPV was decent, glad Sheamus's reign is over, but sad that Ziggler didn't cash in. Glad CM Punk won, and Ryback still looked powerful. The tag team division got in some good matches, they were good chemistry teams, not a match of random slapped together teams, and Antonio vs Gabriel was predictable, yet amazing nontheless.