I think people are missing the point here of what's really going on. This isn't countries refusing to negotiate with each other, it's countries honestly expressing their stances. To understand it you really need to see the process unravel the other way like it has with US-Burmese relations recently.
Burma's ruling cartel wants to reform. This is a dangerous position to be in, it makes them look weak. So rather then coming out and saying let's emulate democratic countries, they do stuff like loosening restrictions on the opposition party before the election. Normally the US would be condemning the Burmese government before the election but the US takes note of this shift in policy and doesn't condemn the Burmese government. This wouldn't mean anything if the US didn't have a habit of condemning false elections in the past. It gives wiggle room, the US doesn't come out and praise Burma but intentionally doesn't show hostility either. This lets the Burmese regime keep from looking like it's folding to the US (which would boost the hardliners) and it shows the reform minded leadership that the US is willing to play ball with them.
And the process has continued. Fair elections in some seats was followed by honest praise of those fair elections but not blanket praise for the regime. The Burma reciprocates by letting the US honor the leader of the opposition, showing the Burma is playing ball. In return the leader of the opposition refrains from condemning the government when she has the chance, showing that the opposition will cooperate with the reformers and taking the wind out of the hardliners sails. The opposition leader did this by just honestly saying she appreciated the reforms but wouldn't blanket praise the government. And it goes on from there, step by step, until we are at the point where Burma is releasing it's political prisoners and the US is normalizing trade relations with Burma. The process is smoothed along the way because neither side is going out on blind faith by taking a risk on the other side. And that's why it pays for nations to have a forum to be honest about their intentions in geopolitics. Real diplomacy is facilitated by having a good idea what the other side is going to do.
By contrast consider the US and Saddam pre-Gulf II. Saddam thought Bush didn't want to invade because Bush got on the cameras every week and lied his ass off about not wanting to invade unless forced to. Bush thought Saddam had WMDs because Saddam had purposefully left some doubt about the subject to keep from looking weak. By lying both sides maximized the other's chances of picking a fight without even realizing that's what they were doing.
So I strongly favor nations staking out their positions in international forums as a means of creating the conditions where dialogue is possible. I support Ahmadinejad's freedom to go to the UN and deny the holocaust and I support the right of the US and other nations to condemn that move by walking out. It's much better then us only finding out what each other meant when the bombs start falling.