Context:
Permissive licenses (commonly referred to as “cuck licenses”) like the MIT license allow others to modify your software and release it under an unfree license. Copyleft licenses (like the Gnu General Public License) mandate that all derivative works remain free.
Andrew Tanenbaum developed MINIX, a modular operating system kernel. Intel went ahead and used it to build Management Engine, arguably one of the most widespread and invasive pieces of malware in the world, without even as much as telling him. There’s nothing Tanenbaum could do, since the MIT license allows this.
Erik Andersen is one of the developers of Busybox, a minimal implementation of that’s suited for embedded systems. Many companies tried to steal his code and distribute it with their unfree products, but since it’s protected under the GPL, Busybox developers were able to sue them and gain some money in the process.
Interestingly enough, Tanenbaum doesn’t seem to mind what intel did. But there are some examples out there of people regretting releasing their work under a permissive license.
If you’re the copyright holder, nothing stops you from releasing your work under more than once license. It is not necessary to use permissive licensing; you are perfectly free to release your stuff to the general public with a copyleft license while also granting your company a separate license even with proprietary terms if you want.
Only until you have any other contributor, as you’re then no longer the sole copyright holder. If you still want to work like that you’ll need a CLA.
Sure, but I was taking “all my own OSS stuff” at face value.