Semver isn't the one and only way of versioning stuff. Heck, it's a pretty ridiculous model for projects that do releases based on time rather than features...
That's your opinion. It seems there's a lot of people in the software industry with a different opinion.
I'm not saying it isn't a good thing when version numbers are meaningful. But that's not always the case and even when it's the case, you'd better check what it means for a particular project. There's no generic "scientific" rule about version numbers.