Agreed, I think it's totally fair for the CEO to be a little peeved by the project, and the complaint is about how horrible his handling of it was. This is exacerbated by how unfailingly polite and professional the ex-intern is in the (presumably) unabridged email thread.
We moderate HN less, not more, when YC or a YC startup is involved [1]. That's why the OP has been at #1 all day - normally we downweight indignation posts at least a little, to compensate for the default tendency to massively upvote them, but we haven't touched this thread in any way. I don't think we'd take that so far as to selectively turn off the Who Is Hiring rules, though. It would set a confusing precedent.
[1] https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...
Plus one of the most upvoted topics ever, 4k votes is a lot.
Btw, indicates that it's one good that HN otherwise downweights indignation posts.
A (different) jobs board where the companies posting the jobs do not have control of the comment discussion would be interesting to see - but would need a monetization strategy that ensures it can survive without turning into pay-to-censor junky platforms like Yelp or Glassdoor.
That said, my gut feeling as an outsider is that they feel genuinely burnt by a former employee making something similar to their product. Not just cynically trying to smash the competition. Not that that justifies anything—everyone thinks they're the good guy (well, almost everyone).