While that's very true, these contracts are inherently one-sided. One party owes money, which is fungible. The other party owes a time-limited pupil slot of a year of education.

So by delaying enforcement, or notice of intent to enforce, one party can escape any chance of being forced to perform under the contract. The other party has no such option.

It would seem that for actions against students who never actually attend to be enforceable, there would at least be some sort of notice required, along the lines of "hey, you're still on the hook for this tuition no matter what, so here's your last chance to actually have the kid show up".