People who have the autonomy and backing to do "real AI" and have those kinds of achievements don't change jobs often. If someone has real accomplishments in AI, that person's going to be very hard to hire away, because quality jobs are rare.

For all the hullabaloo, Director isn't that high at Google. He's not being hired as a VP (there are hundreds of those) or Google Fellow. It's not a bad gig, and I'm sure he'll get to work on interesting stuff, but I would have imagined a guy of his caliber getting more.