If I understand it correctly, author specifically asked a top poster for an opinion, and after receiving negative judgement, decided to stop writing "until further notice".

Therefore, please, let's not make this a drama; let's not make it something it obviously is not. Even if you happen to disagree with the negative judgement, there is a huge difference between "hey you, I don't like your recent comments, get out!" and "how do you like my recent comments? -- honestly, I don't -- then I guess I need some rest".

Having said that, I think that this article was a positive contribution, even if it perhaps started with the wrong premises. For example I had a feeling that LW is not exactly what I would like it to be, and I am glad that someone else said it first, and gave me a convenient opportunity to speak my mind. Later from other comments I see that some criticism was wrong. But for me this just means that it is easy to misidentify the exact cause of the discontent, and perhaps a discussion like this can help to identify it.

For example to me it now seems that the website is generally OK, it should just be better organized, because there is a lot of different stuff in "Discussion" and most of it gets quickly scrolled away and forgotten. LW may seem less productive than it really is, because it is a bit disorganized.

Gee what convenient timing.

To the extent that this implies that LessWrong is reacting badly to valid criticisms (and I apologise if you're not)....

That state of affairs ("good post" -> "we don't like" -> "please leave") seems less likely than "bad post" -> "we don't like" -> "please leave". You have to posit that the post's claims are true and that we react badly to these true claims, whereas the "bad post" state doesn't require truthiness of claims and gets "react badly" as a given. I tentatively accept your hypothesis as possible but I'd like a little more evidence before I consider it plausible.