Ok but why? Like I said, if you put CM Punk into a match with the Undertaker at Wrestlemania and he loses to the Undertaker only because it's Wrestlemania, then CM Punk has lost his last 3 PPV matches to guys who don't actively wrestle. You can't really go around calling yourself the best in the world if you can't beat 2 guys who don't wrestle. Why would the WWE do that to a guy who they allowed to carry the WWE Championship for 434 days?
Because it's the Streak. CM Punk losing three PPVs in a row isn't going to damage him in the slightest. It doesn't matter if it was to the Rock (both of which were losses designed to protect Punk in losing - Vinnie Mac started the first match over, Punk actually pinned Rock in the second without a ref), or to the Undertaker. Plus, him calling himself the Best in the World doesn't mean he has to win all the time. Ric Flair, for YEARS, said: "To be the man, you've got to BEAT the man." As it turns out, that happened very often, him getting beat, and it didn't hurt him in the slightest.