> ... but it doesn't follow from that that we should prefer third-party libraries to our own code.

Agreed. The big tragedy of Open Source is that after its initial wave of success it good flooded with freeloaders. If you allow me to repeat myself: The one flaw of the GPL is that it did not offer provisions to prohibit distribution in binary form. "You want free? Better you know how to unpack the tarball and build the project from scratch... all by yourself (No build scripts beyond Makefile permitted, thank you very much)".

Of course, such overzealous GPL would need to also make provisions to accept dual licensing with nice, commercial, royalty seeking licences. That way, everybody gets what they value the most: You want freedom, you pay with sweat; you just want access, you pay in cash.