If they don’t break backwards compatibility, then they shouldn’t increment the major version. That’s what incrementing the major version is for, according to [Semantic Versioning](http://semver.org/). Even if they don’t follow SemVer today, the versioning policy may change in the future, so it’s safe to have an upper bound. New major versions arrive infrequently enough (once a year?) that updating the dependency isn’t an intensive maintenance task.