His good points here are undermined by the profane, emotional high-cortisol crashout. There’s a place for well-written, witty diatribes and polemics, but throwing F-bombs and F-yous into complaints is not that.
When the blog post is under discussion, I think comments critical of it are just as fair game as ones which appreciate it. If the parent poster was emailing the author to make the same complaint then I think the "you don't have to read it" criticism applies, but not so much in a discussion forum. The point is to discuss what we think, even if that is a critical opinion.