What if the blocksize limit were chosen by each node individually? Everyone would set the minimum = send and the maximum =receive.
No that would not work at all. We'd have nodes that have differentiating chain heights which would most likely cause a lot more problems. You can already limit the amount of bandwitdh that you want to spend though (e.g. 'blocksonly' mode).
So for example I would send minimum 2 mb blocks (if full), but accept maximum 6 mb blocks.
Additionally, after some time most blocks will be above the threshold that you set so it becomes ineffective. It just delays the inevitable.
Far too large a contingent would never accept Andresen, Garzik, and the rest of those cronies as the developers.
They used to be good, but now we see them 'contribute' rarely or wrongly (e.g. 'header first mining').