While this particular situation was vile.... and had nothing to do with overbooking-
This is incorrect. Yes, overbooking allows the carrier to maximize profit, but the flier *does* benefit. Lower prices are a side effect of seat use efficiency. Furthermore, consider the alternative: you buy a ticket, and that's the end of it. If you miss your flight, you forfeit the cost.
I recently missed a flight on Delta due to traffic and the dumbass TSA. Delta shrugged and plunked me on the next flight, no fees, no worries. I have no way of knowing, but given how long it's been since I've flown on a non-capacity flight, I'm sure my seat didn't go unused. If they didn't overbook, I doubt the outcome would have been as favorable.
As an aside: I *always* build slop into my travel plans (after all, there are uncertainties in air travel, like weather) and I always volunteer to be bumped. Ticket refund AND $800? Sheeeet, that's this flight free and 2.5 round trips to Vegas for me! I'm in!
Come to think of it, I remember reading about a system a while ago- far in advance, book tickets to/from big college towns around Thanksgiving, head to the airport, and wait for the offers to fly. Worst case, you might have to spend Thanksgiving in Miami. Wouldn't that suck.