At 500 you probably have a 50-50 chance of winning after an early Queen loss, so yes, I get why you say people shouldn't resign.
However, some people are playing purely for enjoyment and have no interest in getting better. Trying to play a game with a Queen down might not be fun for them.
What's worse is when you have a mate in a few moves and they resign...
Why let your opponent have the satisfaction of ending you when you can do it yourself?