Read above please. You cannot import GPL code into BSD licensed code without restricting the code distribution. In the other direction, you can do it and just add a notice about the license. It does not add restrictions to the distribution. Otherwise Linux distributions wouldn’t even have OpenSSH in base install images.
So it’s an argument against restrictive licenses? The more freedom the better? I mean Unix in this case had a too restrictive license?
What? GPL does not restrict freedom, it ensures its continued existence.
Read above please. You cannot import GPL code into BSD licensed code without restricting the code distribution. In the other direction, you can do it and just add a notice about the license. It does not add restrictions to the distribution. Otherwise Linux distributions wouldn’t even have OpenSSH in base install images.
It’s an argument against a license that permits relicensing under a more restrictive license. (E.g. BSD)
Of other software, yes. For example Linux distributions can use the BSD or MIT licensed code without any problems.
But it does not allow to remove the license from the software.
On the other hand GPL code cannot be imported into BSD code without introducing restrictions.