[dsr_]

Actually, it isn't. It's the same underlying principle.

All software must be paid for, with the exception of countries which have an actual public domain. Some software is paid for with money, some with acknowledgments, and some with source code sharing. Sometimes the developer demands postcards, and sometimes they demand that you not use it for evil purposes. All of these are forms of payment.

If you don't pay for it, you don't have certain rights to it.

[necovek]

That's a very liberal use of the verb "pay". Payment is not the same thing as compensation, payment implies money changing hands.

"Licensing" does not have to involve any sort of payment (or even compensation). There are free software licenses with no compensation requirements at all, yet they are not covering public domain software.