This is why it surprises me to see so many people attempting to justify a lack of or wish not to bother learning communication skills or dismiss such as mere "polite words", "noise" or "grease", as if communication were not an incredibly important part of being effective in dealing with humans.

My pet theory based on my own reaction is that Lionhearted erred too far in the other direction while trying to advocate politeness. Here are two methods of framing the same idea that I would find equally rude but for opposite reasons:

"this post would suck less if it had more examples"

"this post was great! It really gave me a lot to think about. Just one tiny thing, I'm really slow so I would appreciate it a lot if you just added a couple of examples to illustrate your points so that people like me can get it more easily :) Thanks!"

Lionhearted isn't quite advocating the second type of comment but comes fairly close. Politeness is hugely important, but there comes a point where it crosses over into fakeness, passive-aggressiveness, and a bunch of other negative behaviours, and I felt like some of his examples crossed that line, or at least stuck a few toes over.