I think a lot of people agree and disagree on 'issues' because if they didn't, they wouldn't know what to make of their time. They would have to actually do something, instead of engaging in debate.
The issue of 'free' debate (freedom of expression) is huge where I come from - home of the famed Mohammad-cartoons. I think a lot of people like to participate in this ongoing debate, because it makes them feel as if 'freedom of expression' actually means something in itself. As if voicing your opinion is the same as being free.
Let me give you a summary of the debate: All agree that freedom of expression is important. But some think we have it, while others think we don't. And so the discussion goes on and on. Both sides think that talking about it will bring us closer to a solution - but the only thing they actually talk about, is whether there is a problem or not.
If you can't agree on the problem, the solution never becomes an issue. The 'debate' can go on forever.
I think the core of the issue is this: We feel less free - so we have to talk about it all the more. And we have to talk about it, because we can conceive of no other way of making ourself free.
Went a bit off topic there. Sorry