Seems like pretty shameful behaviour to me.
Personally I would feel ashamed to know any of them, especially diego who seems to be an abhorrent troll.
So much for 'open'.
I understand that the other side is not helping by consistently misunderstanding everything.
At some point, if I was representing the GPL side in the argument, I'd realize that my attitude is not helping the cause and I would either change my attitude or ask another supporter to take over in a more polite way.
It takes energy to remain polite and nice in such discussions, but that's the price for convincing people. Otherwise, you are just an arrogant brat, even if copyright law is on your side (think RIAA - technically, the law is on their side).
I think it is a bit unfair to expect everyone to know the score all the time. A lot of us humans are pretty rubbish. To be honest I think there is a certain amount of vitriol in their writing that makes me think they are enjoying the feeling of superiority and making the guy squirm. Sure they have the moral high ground but they drag themselves down towards his level with their attitude.