Users come and go in various ways with offsites being one of them. No one is obligated or forced to stay here, but sometimes user migration is for the better. You'll find that normally these people are, well, like a piece of gum on the bottom of your shoe. It's unwanted and you can't wait to get it off. Not everyone who scampers off is a nuisance, but the majority of users are the ones you'd typically mute.