It's not about whether or not someone is a bigot, but whether or not the argument which that someone is arguing is worth being a bigot about.
An open mind, in questions that are not ultimate, is useful. But an open mind about the ultimate foundations either of Theoretical or of Practical Reason is idiocy. If a man's mind is open on these things, let his mouth at least be shut. He can say nothing to the purpose. Outside the Tao there is no ground for criticizing either the Tao or anything else.
Human evolution is essentially the progression of information gathering (knowledge) and consciousness, or the advancement in wisdom. A wise person is willing to learn at all stages of life by using their cognitive abilities open-mindedly to examine contradictory beliefs, and rationally meld various schools of thought into a living philosophy, developing over time a logical and systematic method to maintain and evaluate oneself in order to assist a person not merely survive but thrive.
It's okay to disagree with the thoughts or opinions expressed by other people. That doesn't give you the right to deny any sense they might make. Nor does it give you a right to accuse someone of poorly expressing their beliefs just because you don't like what they are saying. Learn to recognize good writing when you read it, even if it means overcoming your pride and opening your mind beyond what is comfortable.