Because permissive licensing, and free software in general, rightfully comes with a certain cachet, and it turns out some people want the benefits of that reputation, but don’t actually believe in the freedom “to use, copy, modify, and distribute this software for any purpose.” Hence the treadmill from permissive licensing to copyleft, and then later from copyleft to “source available”…

“But software which OpenBSD uses and redistributes must be free to all (be they people or companies), for any purpose they wish to use it, including modification, use, peeing on, or even integration into baby mulching machines or atomic bombs to be dropped on Australia.”

—Theo de Raadt (2001)