Obviously I can't speak for SR-25's buddy, but alot of us left the Corps for other branches for alot of the same reasons:
1. Escape alot of the Mickey Mouse bullshit peculiar (at least we thought) to the Corps - mostly, "being hard for the sake of being hard" - i.e.; sleeping on the ground and eating MRE's when billeting and a mess hall are available. Why? because we're Marines, rooms and hot meals are for pussies! :doh:
2. Wall locker / junk on the bunk inspections? Fuck that noise.
3. Budget. To this day it pisses me off that in order to have decent gear, I had to purchase it out of pocket, when the folks from the other branches I worked with had all of the latest and greatest gear - and it was issued to them.
4. Required B-billets. If I want to be a recruiter or a drill instructor, I'll fucking volunteer.
5. "False motivation": fake ass motherfuckers with high and tights running around screaming "come on devil dog!" "oorah!" all the time, and then promptly fall the fuck out of a formation run. :uhh:
Damn, I didn't realize I was so angry, lmao.
I left in '99. Maybe things have changed, but I doubt it.