His new versioning scheme ("ferver") is built on the premise that "people don't like it when major versions change often." Seems like a fourth version number is the solution, not breaking the semantics of SemVer.

I propose 4Ver. Just add a marketing version to the beginning. Update that one whenever you want (may include breaking changes). Since you have 4 numbers, you can remove the exceptions for the 0th version as well, and make version 0 follow the same rules as everything else. This cleanly separates the marketing/naming aspect of versions from the semantic aspects.