> Semver still communicates intents pretty well. Well run projects will even roll back changes that ended up being semver incompatible

That sounds either worse. Software releases should be immutable, so no changing existing versions.

And also, if X.Y is incompatible (because they screwed up the versioning, as in your example), X.Z should also be incompatible (according to semver), otherwise you break semver twice instead of just once...

> Treating every patch release of Django like a major release would be a major waste of time

Yeah, I guess computing time. If you manually testing each dependency update, your doing something wrong. This should be automated to such level as you feel comfortable stuff is working by just running the tests.