What would happen if twitter removed rel="nofollow"? Couldn't that open the possibility for more spam on twitter? I tend to agree with Google here, but maybe when it comes to social recommendation, Twitter could be recognized as special and specific algorithms could be written to figure out the worth of a recommendation.
I don't think anyone wants to remove the rel=nofollow attribute. I think people are confused why you can't have a social recommendation appear on a serp even if it is a rel=nofollow.