My suggestion is that in the phrasing of the regulation, the longer they wait to get you home the more money they owe you, and that's sort of a built-in enforcement mechanism for them to send you home on the next available flight instead of their next available flight (cash goes from $0 to $1350 over the span of 6 hours) and IMO that's a positive market force thats stronger than any enforcement action, although if you think your rights have been violated feel free to file a complaint against the airline with the DoT.

I have no moral argument against overbooking, its wasteful for them not to do so if their projections show that without it, the seat would go out empty. Sometimes they mess it up, sure, and in those cases they owe you cold hard cash, hotel accommodation IIRC and a flight to your destination anyways. Between the monetary outlay and the social media feedback, as a very frequent traveler (top tier with AA and Alaska this year, that's 190,000 qualifying miles), I feel quite satisfied with the status quo.

Per [1] in 2015, only 0.09% of passengers were denied boarding voluntarily or involuntarily. Involuntarily denied boarding accounts for only 0.0075% (43 out of 613,141) of boarded passengers -- that's four nines -- and my understanding is 2016 performance was even better. You were almost as likely to be hit by lightning each year (1 in 700,000). With those kind of performance metrics, it feels like things are working, or else we need to really get our act together re: lightning strikes :)

[1] https://www.rita.dot.gov/bts/sites/rita.dot.gov.bts/files/pu...