In the last millenium I had a few emails trading with the author. The FSF take the view that there is one definition of Free: It's their way or the highway. Canonical don't conform to this definition of Free, instead they have something different, that probably works better for them.

In a previous life I worked at an Open Source company and we had to put up with zealotry on a daily basis, both externally and internally. On the one hand the FSF see themselves as guardians of the Free Software Movement - a mantle nobody else seems to want to take up. On the other hand, sometimes they act like douches. This is one such time in which the douche element of the FSF comes up for air (in my opinion, and yours may differ, there doesn't appear to be a clear right of wrong).

Canonical own Ubuntu. It's up to them to run it the way they want to. If they want copyright assignment under their terms, that's their choice, not the FSF's. If they don't like it they can always fork it, but of course their fork won't be nearly as popular. This implies that Kuhn wants to have his cake and eat it, or at least eat Canonical's cake and tell them how to mix the ingredients.