The talk about the race is irrelevant, but I think the insult is relevant, if not nice. Perhaps you're still right that this comment shouldn't be at the top, but I have no problem with the sentiment it espouses being at the top. The story reeked of "humble brag" and "first world problems" and there are a lot of comments on this page saying as much. Clearly it was an impression that a lot of people agreed with.
You seem not to understand what the word "relevant" means. To be relevant, the insult should have attacked the point DHH was making. Charitably: you believe the insult was trenchant, and you've confused that for relevance.
The reality is that DHH's material success has little to do with whether setting overly ambitious goals sets people up for psychologically painful failures. If anything, it accentuates his point; you'd think that having DHH's resources would cushion the blow of not winning the 24 Hours Of Le Mans.
The insult doesn't have to attack the point he was making to be relevant to the discussion about the article. The insult was directed at the overall quality of the article and how it was written. That makes it relevant to the discussion about the article. The article came off as whiny with little redeeming qualities, and that is reasonable to discuss whether you agree with his point or not.