The crux of my experience is that when the thing people disagree with you on _isn’t_ racist/homophobic/misogynistic/etc. then they tend to directly name and openly discuss the subject of their disagreement. The general and innocuous sounding term “diversity of thought” tends to get brought out when the opinions themselves are one of those opinions that people don’t want to admit to so openly.

If people are going to disagree about a choice of software license, or technical architecture, or copyright assignment, or even about moderation standards and free speech, they tend to just directly name the thing they are disagreeing about (as we are now).

I’ll give some ground here and say that in some cases “diversity of thought” isn’t raised because the particular person raising the thought wants to say bigoted things, but at the very least it tends to get trotted out to defend speech that ends up driving people away because of either direct overt bigotry or, more often, a pervasive use of dog whistles.

The implication here is of course that it is only worth talking to those that you can convert to your side, which is of course admitting that you are in fact opposed to diverse thoughts. Are you open to change your opinions or do you only expect others to adjust to your standards?

Of course those calling others bigots and using unionically using dog whistles like "dog whistle" is a very opiniated thing to do. Should we also take those things as a sign of irrationality and not engage with their ideas? Perhaps.