When I read the article I was shocked that 2.11/2.12/2.13 could be breaking changes that prevent existing libraries from working, and so badly that they take years to catch up.
Certain languages prioritize backwards compatibility and maintainability over new features / complicated programming stuff. The maintenance burden is dramatically different for different languages in my experience.
Scala's problem is no unified paradigm is proposed or accepted at community level. 'Dumb' languages like Java/Go limited the style choices one programmer could take within the language, but Scala seems to encourage the opposite.