[jmull]

Well, designing a module to be a peer dependency and then not strongly favoring backwards compatibility is a choice. When you make that choice you're probably screwing your users, in the long run.

As a user of modules, if you can detect such module, you can choose not to use it, and save yourself all that future trouble.

Now. Let's see. How many times has react's major version number changed?...

Yes, it's not only react, but boy are they an enthusiastic leader of this approach.