For the people not getting it:
-
They treat morals as opinions.
-
They also treat their personal opinions like they're the absolute best opinion.
Another way:
They think everyone likes different ice cream flavors and that's fine. They like Rocky Road flavor. They also think anyone who doesn't is a monster.
Convictions are one thing. But they need to be logically consistent. Saying morality is subjective but you're evil if you don't subscribe to my personal version is illogical.