> one cares about backwards compatibility, which semver is all about.

Interesting. I'd characterise it more as 'responsibly breaking backwards compatibility'. Just a tool to communicate the nature of changes, a really (really) brief summarising changelog - what's included, breaking changes, non-breaking new features, or just misc. fixes?

I quite like it, but I tried to phrase my top-level comment not to be about it specifically. It would have surprised me to learn that Linux used 'semver' - that doesn't mean there's no semantic meaning to the version numbers it uses though.