Well I can't speak for anyone else but I'd do it because I couldn't give a monkey's if they make a few more quid out of it. It's no skin off my nose. I entered into a contract with them to get a product at a lower than usual rate, didn't fulfil my side of it and suffered the totally foreseen consequences. There's been no trickery or skullduggerey and I don't bear the hotel firm any malice. On the other hand by telling them it might free up a room for someone else, or keep their prices fractionally lower next year etc, etc. Probably not, but the main reason is that to me, the opposite attitude seems a bitter way of dealing with people and it's not the way I've decided to run my life. I know loads of people who'd agree with you though.
For sure, but I suspect that might require a bit more effort than most people would be prepared to go to for a missed booking.