It's true, I don't find any of these arguments to be paarticularly cruel. I think what leads people to believe that there is some meanness in these arguments is that they are unforgiving of intentional ignorance. This is something which many forgive too easily, and so when a person does not leave any room for it, they seem "mean" to those unaccostomed to such intellectual rigor.

I will say that I have yet to decide if the position they hold is about 5% too extreme for my taste, but that's another discussion altogether.

I think thoroughness, intensity, and extreme polarity of viewpoint have been mistaken for malice. Those who hold strong opinions and argue for them well are often seen this way, however.