People do get extremely strongly motivated on idealistic issues. It is better to demonstrate the fitness of your worldview by the quality of your code that the loudness of your dogma. Another strong motivator is practical experience that the process works better than closed source. Anyone who has the very next day recieved a fix for an open source program becomes a convert overnight. This forms a strong positive feedback locking people into the system.
Evolution works on a very broad, but slow front.
Cathedrals work on very narrow fronts, but not much faster. There is something of a anthropic cosmological principle flavour to the whole discussion. We are only discussing the process of the evolution of Linux because something bizarre and wondrous has happened to make us sit up and take note. I'm only reading your article because the process behind Linux strikes me as vastly important to the future of my career. A billion over processes on the 'net have been ignored and are not analyzed here.