Wow. Very high salaries indeed. What I find particularly interesting is that the PhD's clearly have absolutely no incentive of staying in academia. I wonder how bad an effect this has on academia..
There are other reasons to stay in academia --- mostly to do with lifestyle. You have a lot more freedom to work on whatever interests you than in many other career paths.
That's not clear.
The total net worth of Stanford's CS professors is a couple of billion dollars. Yes, Billion.
Then again, they have incredible "deal flow".