Either way, there is more to it than Dale Carnegie.

Well, when reading the text, the reference to Dale Carnegie's work - as well as the author's reflections on that - constitute the pivotal point of the chapter "Why criticism is bad". Without that, what is left except feelings and such?

He even repeats a claim that 99% of people one criticizes "will not see themselves to blame anyway."

That is not how we reached our modern science and academia.

Furthermore, he advises: "It is amazing how often it is you end up in a chair across from someone at a table interviewing you for a job you really need who happens to have worked on an open source project you publically condemned. Whoops."

If one's criticism is well-argued, this may in fact be the tipping point that secures the job. If the criticism was a one-liner on twitter, it may spark a dialogue that generates mutual respect.

My issue with the post is that it throws the baby - ugly or not - out with the bath water.

you should write so that it doesn't read like you are trying so hard.