I cannot say I am surprised, but I am deeply unhappy about this. Enough so that I probably should not have read this thread on vacation, because now I'm going to be bummed out.
I had many PMs with him. A good man, and solid in his principles...but, on so many levels, this team is drifting away from his ideal.
I will let him speak for himself if he ever feels the need to do so. I tried in vain over the last month or so to see if there was anything I could do personally to help him stay. There was nothing...

There were several issues, but I believe the largest is / was the fact that so few care about being #1 overall here. I have to say I could agree with him a little there...we are now at position #3. That may have been the final straw for him, I don't know.