He surrounded in quotes: "We are working on NS for 6 years, how dare you tell something is wrong?" and that seems suspiciously like a paraphrase on his part. I doubt it is a direct quote but rather a way the author wants to describe how he felt over the course of several exchanges.
One of the other supposed quotes, "You are too negative, I can’t help", is a bit more telling.
His other criticisms aside, I actually have no problem with open source support channels (or any support channels really) excluding toxic negativity. Some people seem to assume that complaining is the same as contributing. If the only thing you bring to the table are your complaints then don't be surprised if you get excluded.