Never ascribe to malice that which is adequately explained by incompetence.. :) HN's code is weird in places, e.g. it's possible to accidentally kill your own posts by double-clicking submit (I can't remember why it does this, but there was a sensible-ish explanation)

Probably because of the horrible link-bait title and general inaccuracy of the article. Especially when this link was also on the front-page (a clear, concise description of what happened without the added FUD).

People probably flagged it over the crappy title and the fact that much of the comments were meta discussion.