I didn't downvote you but my guess: because your "opinion" included facts that were so obviously incorrect that they could only be the result of tremendous amounts of bias that make you unable to correctly judge reality. Which makes your "opinion" not a useful contribution on a site that (tries to) value correctness.
If you were able to express your opinion without resorting to tremendous amounts of hyperbolism that make it trivially easy to imagine you as a frothing-at-the-mouth partisan you probably would have been able to more effectively convey whatever it was you wanted to get across to the readers at HackerNews.