I think there is some truth in that. I know it was true for me. When we first got married after her getting pregnant at 17, my first job paid me about $7,000 per year. We lived in crappy section 8 housing and got food stamps -the actual coupons, not the nice hidden credit-card-like thing people get now. It was embarrassing to pull those out. People look at us like moochers. That quality of life was miserable and motivated us to finish school as quickly as possible. We used every resource available to us, welfare, Pell grants, loans, family help, etc. I ended up working two jobs just so my wife could focus on finishing school quicker (she was the smart one!) and we could provide our kid with everything she needed.
The motivator was always improving our quality of life. So yeah, I believe that having a crappy QOL is a huge motivator. The question is: why are some people not that way? Instead of bitching about how unfair MW is, they should be working their asses off -whatever it takes to improve. Unless they are mentally ill or severely disabled, I see no barriers for the people who actually do work hard.