I agree. It's just not what the SemVer standard[1] says.
To be honest, I don't really care about following SemVer exactly. And PHP does follow SemVer if you pretend that the major version number doesn't exist, and the minor version number is really the major one (hence we're just seeing the release of version 5.0 of 'PHP5', rather than 5.5.0 of 'PHP'). This is all pretty easy to understand and it's not a bad way of doing things, but claims that PHP follows SemVer are incorrect and will cause confusion.
Breaking changes in each is fine.