As true as that is, it's orthogonal to the actual debate at hand. There are plenty of good reasons to pick Python, or Java, or Scala, over C/C++. But this article claims performance is one of those reasons, and then crafts a particularly leaky argument to carry that claim.
I read the article more like: "Writing a program in C is no guarantee of having a fast program. Here are a few examples." (Of both places where C is not the best for speed, and other languages giving good results.)
I think your idea of "the actual debate at hand" is too narrowly focused. As a reader of HN, I'm generally interested in how to get things done in a reasonably efficient manner. I find that "get it running, profile it, understand it, then optimize" is a good thing to think about when discussing performance. It cuts through a lot of delusions people have about their ability to write fast code. (Especially when they try to do it up-front.)
