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You misunderstood me - while technically possible, the ability to incorporate GPL software into proprietary software products is severely restricted. And yes, having to use out-of-process extensions to avoid the GPL propagation to proprietary code is limiting.
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GPL restricts usage and is a close cousin of those non-commercial licenses. Permissive licenses do exist. Complying with licenses is itself a choice. GPL violation is the software equivalent of pirating a movie. Many people choose not to respect software licenses anyway.
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You're playing on the words here - yes, the GPL is applicable at distribution time, but having to distribute essential components of your software separately comes with several restrictions on how you can use it, the first one being that you can't link it statically.
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Developers are the users of the source code. Both developers and other users distribute software all the time. Distributing software is part of using it. Source code doesn't do any good without developers to work with it and distribute software to end users based on their work.
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