I'm sorry, I may be misunderstanding what you're asking, but it seems you're asking about the old GPL vs. BSD/Apache/whatever, free software vs. open source software. If I'm misunderstanding you, I apologize.
[1] explains the difference. Why is a BSD license not free but the GPL is? Because a BSD type license allows you to take software and turn it into non-free software. IOW, you could take BSD software, base your new software on that software and not release your changes or your source code.
I'm not imparting morality here, just trying to explain to you the difference between BSD and GPL and why some consider BSD to be not free.
GPL ensures that any derivatives will also remain open source, permissive licencing permits proprietary derivatives.
The benefits of GPL when it comes to derivatives is that all the code will remain open, so if someone forks project A into B and make changes, project A can incorporate those changes or maybe everyone jumps onto project B, and perhaps someone will later combine project A and project B into forked project C, etc.
Either way the source code of all derivatives remain open.
With permissive licencing there is the option of proprietary forks, which means that nothing ensures that any changes made in a proprietary derivative will ever reach the open project. That doesn't mean that no code will be contributed back, but again there's nothing saying it will.
> Because a BSD type license allows you to take software and turn it into non-free software.
No, it doesn't. A BSD-type license doesn't let a third party make the software anything but BSD-licensed software. It does let them distribute derivatives under different licenses, but that doesn't change anything about the original.
I apologize, I should have said it allows you to turn a derivative work into non-free software. The link explains what is really meant (note that it isn't my opinion here).
[1] explains the difference. Why is a BSD license not free but the GPL is? Because a BSD type license allows you to take software and turn it into non-free software. IOW, you could take BSD software, base your new software on that software and not release your changes or your source code.
I'm not imparting morality here, just trying to explain to you the difference between BSD and GPL and why some consider BSD to be not free.
[1] http://understandinglimited.com/2007/12/13/rms-on-bsd-vs-gpl...