While I agree that there should be a system that prevents simple alt creation, I think that some moderation policy changes should come first. Toribash is probably the only game I know where you can get a real ban for calling someone a dick (other words may be used, it doesn't change the point). Yes people should know how to behave but due to the lack of tools allowing to mute players instead of banning or having any other sort of softer punishment killing off the possibility of creating alts would be kinda weird. You can get restricted from playing a game if you shitpost in market on forum, after all.

If we ever get to actually implementing an anti-alt system, I'd like it to be more harsh though: you can register only one account from your steam ID (email required, no confirmation needed); if you register an account using a standalone version then you have to confirm your email and your account's functionality is restricted (transfers mainly) for certain amount of time / until you play certain number of games. This would make accounts more valuable than they are now (because you can't just go and make a new one any moment even if you get a new email) and open possibilities for having game rewards.