You are not getting my point. The point was, that the ability of the GPL to enforce source sharing is limited. Where source sharing and redistribution are not desired, GPL licensed software just isn't used. Or used in a way that it does not affect the propriatary parts.
The whole argument of Stallman is that you don't give companies the choice to use permissively licensed software (by making it economically impossible for them to rewrite the entire body of free software).
I think "there isn't enough software under the GPL" is not a criticism of the GPL's effectiveness. If anything it supports the GPL as a method for ensuring user freedom.
If the only open source software available to companies were GPLed software, they would not switch their product to GPL, but rather not use open source software. GPL isn't making companies share source which they don't want to share, they just avoid anything GPL. That is what I meant with the limited powers of GPL.
This isn't about not wanting to "give back" to the community, companies using permissive licensed software are contributing back. It is about that the GPL is incompatible with the business model of all companies which are licensing (selling) the software they produce.
