I have to say that it doesn't really encourage respect to call someone's point stupid in general, even if it's not an insult it isn't compatible with the theme of respect. At least when curbing respect, that should be discouraged until respect and intelligence is restored, then it might be interesting to leave some room for poking fun at each other that way. But it would be a priviledge earned by the community building respect.
It's like you can't make fun of your friend until you've built enough credit with him to feel free to pull his/her leg a little.
No, I agree - I'm certainly not encouraging it.
As I've already said I'd like people to engage in discussions in a respectful and open-minded way - take on board different points of views and express your own with some form of evidence / backup.
At the same time, I understand that most people can get heated at times (I'm as guilty as anyone) and it can be frustrating when you make a point and people still don't understand or accept it. I can understand situations where someone feels that someone else's behaviour is "stupid" or "idiotic" and I understand if people feel the need to point that out. It isn't ideal by any means and straddles the line of becoming disrespectful but I think it is different to say that what someone is saying is stupid compared to calling someone stupid which is far more personal and a direct insult.
The real world isn't black and white unfortunately and with grey areas like this I trust moderators to make a decision based on the context.