Seems like a silly reason to disregard someone or something.
I'll add that I think such an attitude is one of the greater dangers we face as a society in the USA. Assigning people or ideas to categories and dismissing them wholesale rather than looking for the truth or wisdom that may be contained within. Rarely is an idea presented without some form of metaphorical shell to be shucked. Do your due diligence, cast aside your prejudices, and listen with empathy and intent to understand. We will all prosper for it.
I must be in a good mood. Normally my answer is to burn it all with extreme prejudice.
Prejudice in the first paragraph to mean: Bias.
Prejudice in the second paragraph to mean: Cause harm.
Sportsmanship killed CF