Pay day loans are generally good _for the borrower_ - they aren't just window breaking. The consequences of missing an important payment can be way worse than the high interest on the pay day loan, e.g. if you don't pay for a course in time, they disenroll you and you no longer get to take the course; if you don't pay rent in time, you might get eviction proceedings filed against you; if you don't pay for your car repairs the garage will not return your car and you will lose time every day taking public transport.
I won't argue that the availability of payloans (or any other product) is a net positive for the rational consumer. I'd still be willing to bet that (ceteris paribus) a society like the ones we live in is better off without them than with.
(Coda: You might say that's impossible, and local loan sharks will spring up to meet the need. That's probably true, but at least those guys merely break your legs, rather than advertising incessantly on daytime tv.)
