No one said you're supposed to contact anyone about the spam. If the problem could be solved on their end, this catch-all/tagging solution wouldn't need to exist in the first place. The assumption is that people can't be trusted with your email address, so you create a way that their incompetence/malice can't hurt you, and then you go about your business.

Imagine criticizing helmets because children keep falling off their bikes.

Btw 90+5+5+5=105%.