Being an officer in the military is also a hard go unless you like being a politician with a gun. Gone are the days when mere ability and talent as a leader would get you to O-6 and beyond; now you're lucky to make O-4 if you aren't playing politics more than being a warrior/sailor/etc. This is why so many good officers get out after one tour: they see who is left above them on the ladder and what those people did to get there and they would rather apply their talents in civilian life.

Can you make a full pension lingering at O-4, or would you be forced out for non-advancement?

Not surprising. I would imagine that if the number of officers needed is shrinking it's a pretty bad environment for survival. There's a need for good people everywhere, and people will naturally gravitate to more gain, less pain.

I don't think it's a path-of-least resistance attitude but more "I would rather not give my all and not be passed over because I'm not into ass-kissing and other BS." I realize the civilian world is full of this as well but at least here we have the option of starting up our own thing and running with that.