I don't think it's horrible. First, it prevents abuse, and second it adds extra social pressure to not cheat if you're using this since you know if you get caught all your family comes with you. Sure, maybe some parent sharing with a stupid child it sucks, but I use this with my brother and we're both adults and know it isn't an issue for either of us. I don't really care if this prevents more cheaters from existing. The harm will be very minimal, with pretty good upsides for the vast majority of people.