JUnit plugin is not an API plugin. It contributes logic like Publishers and UI. So any plugin developer adding dependency on this "API plugin" gets more stuff then he would expect.
IMHO it is critical for API plugin, and now the fixing is more complicated due to the Blue Ocean 1.0 release.But it still requires a Fix (e.g. decoupling of "Test API Plugin" from JUnit or just a logic cleanup in order to make the dependency optional) . CC James Dumay