Yeah, I joined for the GI Bill (and steady work, as I was 26 and working at a cable television call center), and ended up staying in because the job I was doing was preferable to what I had wanted to get a degree to do. I went into aviation, though (helicopter flight mechanic and avionics electrical technician). It's been an awesome job and I get to retire in 6 years and get a paycheck for the rest of my life! And my kids get my GI Bill, so between the two of them they have 4 years of college paid (while also getting an allowance for housing).

I've never had to shoot at anybody or get shot at and have been in operational jobs my whole career. I've never been put in a situation where I had to do something morally questionable.

That said, if I went for a non-aviation rate I'd probably have done 4 and out, and get my degree. The other rates seem either boring or miserable (to me). Then again, the vast majority of civilians jobs feel the same way to me, so YMMV.