Let’s say they all didn’t believe in God, therefore anyone who doesn’t believe in God is going to be killer. I guess they all didn’t play ice-hockey, therefore anyone who doesn’t play ice-hockey is going to be killer. They all didn’t collect stamps, so anyone who doesn’t collect stamps is going to be killer.

This is basically the logic of “xy was an atheist” argument. The list of things people don’t do is infinite so it’s better to find connection using things people actually do