On the yes part, don't think I would like the thumbs down because it would discourage dissenting opinions. People of dissenting opinions often have rational reasons for them that happen to be unpopular.
As for the 2nd sentence, those that do that wouldn’t get a negative remark or thumbs down from me. I appreciate a well thought out and reasoned opinion regardless whether I agree with it or not. It gives both parties something to work with in terms of a back and forth discussion.
It’s all a moot point, as nothing will be changing. Just expounding on my initial sarcastic comment.