If I was in their position, I would do whatever it took to be acquitted.
Would you? Suppose you were the guy who runs the Pirate Bay: Your entire identity and celebrity rests on the fact that this website is still accessible. Do certain things and you are forever known as a sell-out, especially after the ridiculous amount of media attention you have heaped on yourself (even in the days before they started being idiots about the trial).
I think there are certain things you wouldn't sacrifice. I think there are social contracts you would choose not to violate.
Do I think these guys really believe in the freedom of information, in the freedom of speech, in the "free format" garbage that gets spewed all over this and other websites? No, of course not. But, their followers certainly do, and that's all that matters here.
I think this is just one side of the cost-benefit analysis. Risk jail time and large fines, but gain media attention and more devout fans.
I don't think these guys are any more brave or principled or high-minded than the guy who goes to jail for his gang rather than snitch on the leader. You'd think that selfish, personal greed would take over, but at some point, you can't sacrifice your identity.