Presumably those accounts are dead because of repeated rule breaking, not because their specific post in this thread broke the rules. And there might be more dead comments here on average because politics+tech draws a lot of a certain type of commenter(the type of commenter that might get banned)
The first of those (11 months ago) is where the account was banned.
If you have specific questions on accounts, users, sites, comments, posts, etc., which you feel are improperly flagged, killed, or banned, you can always email the mods at hn@ycombinator.com. I do this frequently, usually with suggestions (e.g., title or URL changes), sometimes with questions (earlier today a site which showed up dead, turns out it's a hard paywall, which I eventually tracked down dang's comment on, though not in an easily-searchable way).
