What really happens is:
1) Project is open source
2) People use the project because it is open source
3) People contribute bug reports and fixes, creating value and improving the open source project because it is open source
4) People spread the word about the project, free marketing because it is open source
5) Maintainers decide to relicense, privatizing the value created by the community.
The "success" was a social phenomenon, not merely the efforts of the maintainers.
Relicensing is a betrayal of the community that was built around the software.