Ryder losing the belt had absolutely nothing to do with Ryder at all. It was done as a continuation of both the Kane/Cena angle and the Punk/Laurinaitis angle.
It further sells the damage that Kane can inflict, making Kane more of a monster, so that when Cena and Kane do finally meet, it's more important. You have to make Kane as big a monster as possible in order to make the feud with Cena, which is really just a placeholder feud until the Rock returns closer to Wrestlemania, more interesting. Since Zach Ryder is a friend of Cena's having Ryder be injured enough to not really be able to compete in a fair competition against Swagger further enrages Cena.
By having Laurinaitis not open the envelope until after the match, it also furthers the Punk storyline. It's another example of Johnny Ace screwing people. Punk will claim that he knew that Ryder wasn't cleared to wrestle, and let him do so anyway. The obvious inference is that an honest Vice President of Talent Relations and Interim RAW General Manager would have reversed the decision based on Ryder not being cleared to wrestle, thus giving him the belt back...and since Johnny Ace didn't do it, he was crooked. We all know he is crooked, but this would cement that idea even more. Look for this or something similar to be addressed next week.
Who did it benefit more? Tough to say. It benefited John Cena, Kane, CM Punk, John Laurinaitis and Jack Swagger (obviously), but I would argue that the person it benefited the most the loser himself, Zach Ryder.
Why would I say that? How can the guy who just LOST the belt end up looking the best out of it? Because it means that a midcard wrestler, who a lot of the IWC despises as a no talent hack could have just become an integral part of the two biggest RAW main event storylines heading into the Rumble. Zach Ryder, love him or hate him, MATTERS to the WWE right now.