> Often, that abrasiveness is a side effect of their talent

I think this is the crux of the argument. That there are people who are highly technical and good at soft skills proves that it is not a necessary side-effect.

Why would it be? What evidence is there that there is a meaningful correlation beyond pure anecdotes?

I agree with the author. Here's my take: extraordinarily talented engineers have been given carte blanche in this regard because there is an well accepted stereotype. If we stopped accepting this behavior, I believe engineers will adapt, or be replaced by those who can.

I don't expect everybody to be a social butterfly, but I do expect people not to be an outright ass (i.e. 'abrasive personalities')