CNN reports Transportation Sec's comments on the incident:
Feds: Regional carrier, not crew, at fault in plane's tarmac stranding - CNN.com
"This could also be legally classified as unlawful detainment (as well as many other definitions) justifying a 911 call and the airline, airport and federal government need to be held accountable. The jail time would just increase the financial settlement."
This was my feeling on the issue; passengers were being held on the aircraft against their will, indeed having also being flown to an airport to which they didn't want to fly in the first place.
If nothing else, hopefully this incident will spur the development of an action plan to deal with situations like this. Talking sense to airlines and appealing for common sense almost certainly will not work, but if they're hit by large fines/court settlements and there is legal precedent, you can bet that they will begin to understand. It's sad that it comes down to "talking to them in a language they understand" (i.e. money), but if there is a positive outcome, it will hopefully be that we won't see a repeat of a situation like this.