Or you could say that Lesnar is the same guy who jobbed twice to HHH and Cena and has admitted that he is only doing it for the money.
Honestly, who gives a fuck what he's doing it for? Lesnar jobbed to Cena because it was Vince's way of punishing him for leaving in 2004, and he lost to Triple H because Triple H is the egomaniac who runs the company and always has to get his win back on somebody he beats so he doesn't look like he's lowering himself. He's supremely insecure and has nearly unlimited power, of course he beat Lesnar. We're talking about CM Punk here, not Cena or Triple H. And Lesnar is going into WrestleMania next, no less. They don't want their special attraction looking bad.
He isn't the type of guy who cares about win/loss records so he is just being used to give others momentum and big wins.
Clearly THEY care about his win/loss record which is why as soon as he lost to Triple H, he promptly got his win back to even things up. We probably won't see Brock until Mania, and he's scheduled to fight Undertaker at this point, so you better believe he's winning.
CM Punk losing to big stars is a reason why I think he will beat Lesnar. The win against Lesnar will compensate those losses and make him look like a threat again.
For what? What's he gonna be doing until he wins the Royal Rumble, in SIX MONTHS? Probably not a whole hell of a lot tbh. They're more focused on protecting Lesnar which is precisely the reason the Punk match is happening, to give him fodder to beat to up his stats so that when he faces Taker he has a winning record and the last thing we saw of Lesnar, he was destroying a main eventer.