I happen to know the guy from the linked article from several meetups here in Germany and while I stick to the old saying that if you don't have anything nice to say about a person it's better to say nothing at all, I just want to say that I can somewhat relate as I do get cringe feelings as well. Try listening to one of his talks and make up your own mind.

On a side note: It's interesting to see a list of stated facts that a _professional C++ developer must know_ without having any real world, industrial experience with small/middle or large codebases for the last 15+ years. So there's that.