Many feel this way about those that knee-jerk to racism without any other consideration, or attack with an ad hominem, feeling justified in doing so because their opponent is "racist". They can never even get to the actual topic of conversation without first wading through accusation after accusation, definitions, misrepresentations, misquotes, and so on. I think many of them prefer it this way. Better to stay focused on the evil racist bastards than actually have an uncomfortable but adult conversation. It's a shutting down of the argument.
ETA: What really gets to me about this behavior is that crying wolf all the time can bring deaf ears when actual cases of racism are evident.
Exactly what does this have to do with my sourced observation that Harris does not, in fact, think Islamophobia exists, under any circumstances? Which is a patently absurd viewpoint that only a jackass would hold?