(And no one arm wrestles Mormons to come into these online forums, either)
If Mormons don't like these posts, they can simply avoid them. Right?
Absolutely! They are free to do so! I think the real issue here comes down to freedom, and it's very basic. In order to be free to believe what you believe, you have to be willing to let the next guy believe what he believes. You don't have to buy what he believes, just understand that he has a right to his own beliefs.
Otherwise, no one is free.