Why does society and even liberal christians think that being a fundamental christian is bad?

I don't object to anyone's sincere religious beliefs, even those I think are wrong. I do definitely object to people trying to p legislation based on their beliefs to make others who have different beliefs follow their rules. Also people who think they can convince me by making the same claims without offering any independent proof. Or people who expect me to take quotes from the Bible as proof that the Bible is revealed, infallible truth. Not to mention people who act like me disagreeing with them makes me evil or inferior. If even Buddhists treated me that way, I would object to them too.