I think the use of the word "tolerance" here muddies things.
To the extent that tolerance is a virtue, it refers to tolerating other people for what they are, not what they do. There are gray areas here of course, but there are plenty of places where that distinction is clear.
I don't think political tolerance is inherently virtuous. If a coworker tells me they don't think women are suited for technical work then I don't feel any moral obligation to be "tolerant" of that viewpoint.
> To the extent that tolerance is a virtue, it refers to tolerating other people for what they are, not what they do. There are gray areas here of course
The gray areas are miles wide in many cases. Tolerance of what people are is fairly easy for most people to agree on, but in some cases what people do and what people are is disagreed upon. That is, to some degree, the crux of the debate about homosexuality still. People disagree on whether it's something people do, or are. At the same time, an older debate under similar grounds (but, ironically with less evidence for it being towards the are end of the spectrum) is religion. Are you a Christian, Jew or Muslim, or do you just practice those religions?
I don't think boiling it down to are and do particularly helps for a lot of the really controversial topics we are currently dealing with.
Except you're conflating a person thinks with what they do. It is still entirely possible for your hypothetical coworker to give a more honest evaluation of a female colleague's tech work than for one who was a women's rights firebrand and perhaps prone to overlook poor female performance because of his or her own biases. You are right to demand impartiality where judgment affects another person's equality. It's unfair however to assume without evidence that someone is incapable of impartiality because of what they think.
I am reminded of an old quote from George Washington:
"It is now no more that toleration is spoken of, as if it was by the indulgence of one class of people, that another enjoyed the exercise of their inherent natural rights. For happily the Government of the United States, which gives to bigotry no sanction, to persecution no assistance requires only that they who live under its protection should demean themselves as good citizens, in giving it on all occasions their effectual support." [1]
"Tolerance" has a clear power dynamic. One group allows another group to exist. It is therefore shouldn't be looked at as the ultimate goal of a just society. Instead we should simply ask that people are "good citizens."
Whether your coworker believes women don't make good tech workers should be irrelevant to you. What should matter is whether they are a good employee and whether their views manifest themselves in anyway that hurts anyone else (e.g. they should not be in a position to supervise other employees if they can't prevent their beliefs from harming those employees)
Have you heard this? I have not. I have heard people make the case that there are very minor biological differences between men and women, and seen them get tainted with the brush of holding a far different view.
To the extent that tolerance is a virtue, it refers to tolerating other people for what they are, not what they do. There are gray areas here of course, but there are plenty of places where that distinction is clear.
I don't think political tolerance is inherently virtuous. If a coworker tells me they don't think women are suited for technical work then I don't feel any moral obligation to be "tolerant" of that viewpoint.