Isn't cooperative mining a form of communism ?
Personnaly I gave this a thought and I think it's useless and much harder to do than one might think.
First I thought it was a problem if only a few nodes were capable of mining. Now I don't care anymore. Even if only one was mining all new bitcoins, I wouldn't care much. This node would do all the work recquired, and in the best way. Plus, anyone can take its place if it can hash more.
There is nothing wrong with voluntary communism. Not sure if you were implying that there is or not. I think someone has worked out the details of making it work, but I'm not sure.