Here's why:
That cartoon really sums it up well. Conservatives not welcome. The problem is that once they go down that path they have to split hairs about what is further allowed or not, alienating even more people. It is a losing approach. They should focus on delivering a even-handed, respectful platform, the town square. Applies rules to all parties evenly and recognize that not everyone is in favor of their Democratic, liberal, progressive, socialist fascism. It IS OKAY to think Christianity is okay, Islam is evil, homosexuality is a perversion, gender and race identity are wrong or abused, capitalism is good, etc.