> I consider this the absolutely worst reason to use the GPL.
I think rms is right here. Selling exceptions is a good thing. It's certainly no worse than selling proprietary forks of non-copyleft free software:
http://www.gnu.org/philosophy/selling-exceptions.html
Why would it be ok to take non-copyleft software like clang and make proprietary forks with it, but not ok to sell exceptions in order to fund copyleft software?
EDIT: As an Octave developer, I greatly respect how FFTW's copyleft is used, for example. Matlab buys a license exception to use FFTW. Octave gets FFTW under the terms of the GPLv3, just like Octave itself, which we in turn contribute back to everyone else. Matlab and Octave are both using the exact same library for Fourier tranforms.
I like this model. Everyone is paying one way or another, no freeloaders, just lots of freedom.