I think the discussion has gone off the rails here by arguing about the content of your opinions. It's almost certainly the signaling properties rather than the content that caused the initial downvotes. I predict that you're perfectly capable of writing a well-received animal-rights post here, and that this would perhaps get a few people to change to vegetarianism. (Contra Eliezer, you could even begin such a post by stating that eating meat goes against the proper extrapolation of our rationalist values, and still get upvoted.)

What you did here (from my perspective) was to overtly signal your moral superiority to the rest of us, in a context that wasn't devoted to this discussion. That behavior is characteristically downvoted to oblivion here (with a few exceptions- occasionally someone manages to do this wittily or trigger the right applause light; we're still human!).

I approve of this group norm- it leads to discussions with more substance than signaling. I hope you understand that we don't mean any disrespect to your ideas (well, most of us don't), and we'd be open to hearing your case on the issue.