There's a big difference between being punished retroactively for good behavior, and being locked out--which I took to mean as preemptively prohibited--from undertaking that good behavior in the first place. Your follow-up quote explains that what you meant was the government punishing good behavior, which makes more sense to me.

that being said, i still think there's enough internal and external factors in play in savings and earnings decisions, at least on the scale of widespread federal education policy, that it effectively obviates the moral hazard argument you're making.