Earlier quoted context omitted.
His "contribution" was arguably wrong, his effort was minimal, and his attitude was poisonous. If you want an encyclopedia where the opinions of "domain experts" trump consensus, then use Citizendium.
What you're effectively saying is that contributions to Wikipedia should be reserved for people who are highly involved with Wikipedia already. Outsider? No chance. Why allow every peasant to add stuff, right?. I derive this assumption from your statement that his contribution, effort and attitude was "wrong", "minimal", and "poisonous". I don't see any of that. I see a rant following a genuine effort to contribute,…
Contributions to Wikipedia aren't reserved for people already involved, but following prominently posted instructions and reading some documentation are requirements, for good reason. This is not the story of a mature and reasonable person whose hard work was unfairly dismissed by the secret Wikipedia cabal. This is the story of a temper tantrum thrown by a self-proclaimed "expert" when his ego was damaged.