They shouldn't, because there would then be no confidence in the coin. It has one job to do, and when it fails, everybody dumps it. UST (Luna) went months ago.
I've had some UST sitting in an exodus wallet since then wondering what to do with it. My exchange isn't accepting it so although it has value I can't actually sell it to anybody and now Exodus have just decided to delete it from my wallet altogether.
It's as if, having had 95% of the value stolen, somebody thinks it's okay to steal the other 5%. Bastards, basically.