>>26
I've made a fortune by writing and selling my own free software. My niche is to work as a software consultant that specializes in writing free software replacements to proprietary software. My customers are perfectly welcome to copy and modify then redistribute the software that I've sold to them; in actual practice they don't do this because that isn't a normal part of their business function. I write software that is perfectly designed for their business and they have no interest in doing work such as doing tech support for supposed software users, making further changes for the sake of supposed software users, or collaborating software development with supposed software users. I am perfectly happy for my customers to start doing this if that was their desire as they are entitled under the GPLv3 or later.