By "devalue" you mean "lower the price of" which... seems fine? Useful assets being cheaper is a good thing.
Does your car drive worse if no one will buy it?
I'm not saying it doesn't suck to overpay for something, but you can't expect too much pity when you lose money speculating.
Or you think the best way to deal with people getting scammed, is to make sure everyone gets scammed, to avoid being unfair to the initial victims of the scam. For example if Billy put $200 in a Ponzi scheme we should tax everyone else $200 to make it fair.