Yeah, this is my experience. I've posted lots of comments and even whole posts critical of Eliezer on this point or that point and have been upvoted heavily because I made my point and defended it well.

So I'm not sure the karma system makes it so you can't voice contrarian opinions. The karma system seems to enforce the idea that you defend what you say competently.

Case in point: Mitchell's heavily upvoted comment to which we are now responding.