Well he's writing that way. Did you even read the post? He insults the entire HN community for stuff that most people can't even recall or find evidence of.
Also, if you read the post it sounds like he's not a very active user. He is likely completely disconnected from how this community works.
> He has nearly 9000 karma which you don't get by being completely disconnected from how this community works.
Sure you can. Karma is mostly an indicator of tending to post things that are popular, and there's a pretty big bonus to that if you happen to have name recognition as a popular figure. If you're a popular figure and your natural inclination in writing is in a direction which would be generally well-received on HN, you can get lots of karma whether or not you have much understanding of the community.
(Of course, if you wanted to maximize your karma, developing an understanding of the community would help. But that understanding isn't a necessary precondition to getting a high karma score.)
