United should have offered more $ to get people to volunteer.
Saying that they couldn't get volunteers is like saying you can't hire developers - you can get either if you offer the market rate. Instead, United decided to use muscle instead of compensating customers for what was United's mistake.
I don't think the level of moral outrage you're expressing is commensurate with the position "the only thing United did wrong was setting their cap for overbooked flight compensation too low." And in any case, that cap is set by the department of transportation.
The "cap" is a limit on how much the airline must pay, not on how much they can pay in order to involuntarily dis-board a passenger. There was nothing stopping them from paying the passenger who "bid" $1600 to solve the problem they created in the first place.
Are you sure? Most of the articles I've read indicated that the cap was UP TO 400% of the ticket price with a maximum of $1,350 which seems to indicate that the cap is a maximum. Although I will say if the airline offered cash instead of vouchers I'm sure more people would have volunteered.
"If the airline arranges substitute transportation that is scheduled to arrive at your destination between one and two hours after your original arrival time (between one and four hours on international flights), the airline must pay you an amount equal to 200% of your one-way fare to your final destination that day, with a $675 maximum."
It certainly looks like they are specifying a maximum compensation for the relevant situation here.
But suppose it were entirely up to United. Whenever I've asked people what United should have done instead, "offer more money!" is really the only response I've gotten. Even if the amount were much higher, there could still be scenarios in which people would refuse it for whatever reason. And even if it were entirely up to United, that seems like very minor mistake, if you could call it that. And certainly nothing that should cause anything resembling "moral outrage." Particularly when their flight bump compensation is in line with all other major airlines.
Saying that they couldn't get volunteers is like saying you can't hire developers - you can get either if you offer the market rate. Instead, United decided to use muscle instead of compensating customers for what was United's mistake.