Possibly a talent acquisition of Levchin. If he doesn't quit, it seems like a good purchase.
If that's the case, why not just pay him $100 million directly and cut out the middlemen?
Those folks are taking a huge financial hit. He convinces Google to buy the company as a favor to them. If he just dumps the company and takes a huge bonus from Google, he loses a lot of friends, and has a hell of a time getting funding next time.
So he's going to do his time at Google. 5 years of startup purgatory. And when he comes out, he'll have a few friends ready to put a couple million behind his next venture.