"Do such people still rise to leadership in government? Or are they all maximizing click-thru for SV companies?"

Many of the people I know got out of government contract work because the policies and work environment were messed up.

There are only a couple idealistic people that I know of who joined government work after other careers. Technically one of those people was trading in even worse policies/leadership in the military for a defense contraring job as a civilian.

So even the people who are idealistic aren't wanting to stick around, especially if policies and politics are starting to get in the way of the mission.