I don't complain in Ask HN posts when stuff I upvoted is flagged off the frontpage. If you have a problem with moderation, email the moderators, like everyone else.
I have an issue with flagging active and important stories, hiding upvoted comments, silently de-ranking stories without any notification, etc.
Straw-man all you like, there's no justification for this.
I also believe this is a terribly important topic to discuss, with special relevance for the HN community (not that I need to prove that, the number of comments speaks for itself).
I have emailed the mods, and will update with the reply I get (if I don't end up banned).