Always good to see people who are intolerant of Christians. If you can be tolerant of gays, and tolerant of people speaking ideas you disagree with, why can't you be tolerant of Muslims, Jews, and Christians too?>
Because religious groups propagate ideas that are known to be false. You can without a doubt easily prove that the world is older than 4,000 years, yet there are many Christians that will tell you otherwise.
Example: I try to convince you that I had a flying cow in my backyard. I sincerely believed it try to teach your children that cows can fly if you sacrifice food an money to them. Is it alright for me to go around saying this, taking money and food from the innocent and weak? No, this is immoral whether I believe it is true or not.
I agree that the world is not perfect, and scarier everyday. But I feel like it's a heck of a lot better than the time when the church ran everything - we now refer to that as the Dark Ages.