Capitalist view of Open Source
Since the GPL clearly works according to principles approved of by the Capitalist ideal, those who seek to have it outlawed are trying to interfere with individual freedom. They are therefore statist and the real enemies of Capitalism. When Microsoft talks about the need to educate policy makers about the "threat" from Open Source, it is posing a statist threat to capitalist values.
There are many who will not be convinced by the reasoning above. They will argue that Open Source may use capitalistic mechanisms, but it does so in order to undermine Capitalism and achieve socialistic objectives. This argument is meaningless, because any system that obeys all the principles of Capitalism is, by definition, Capitalism. If socialists are also happy with it, then it simply means that Open source has been able to bring to an amicable end one of history's longest-running debates.
Supporters of Open Source need not be embarrassed if no corporation makes money from Open Source. Capitalism does not guarantee corporations a profit, and Open Source does not need such petty "proof" of its capitalist credentials. What is important is that Open Source works exactly according to the definition of Capitalism by one of its most hardline advocates. Therefore, no capitalist of any (milder) shade can doubt its credentials. While many corporations may make significantly less money thanks to the disruptive effect of Open Source, Open Source will continue to create wealth for its creators to enjoy, and to share with everyone of their own free will.
That is the ultimate measure of its value.