I am in favour of banning sponsored themes for all the reasons you stated in your article, Matt. WordPress IS free and anyone making financial gain from your work is cheating, somehow.
I came up against a similar argument (and lost) which was almost the reverse of the current situation, when I was making themes for an app which shall remain nameless (its pretty much fallen into disuse anyway by most people)... many of us spent long hours beavering away at our themes which we released for free, and then the creator of the app bundled them with it as a selling point - without the themes, the app had no pizazz. Was he right to do this? I don't think so. And likewise I don't think anyone should be making money by stealth in the way described.
To the individual who objected to the default blogroll... why on earth should the people who created and who have put soo much into WordPress NOT be permitted to have their links there? geez!! Delete them if they don't fit your site... but don't complain about that, for heavens sake.