The title is misleading. The point that the author is actually trying to make is that adding Scala to an existing project can be harmful. He does not say that S

The title is misleading. The point that the author is actually trying to make is that adding Scala to an existing project can be harmful. He does not say that Scala is inherently harmful for large enterprise projects, in fact, he explicitly states the exact opposite: Neither Geir nor I consider Scala inherently harmful to a large-scale programming project. I would argue here that adding any language to an existing project would have at least some of the drawbacks that the author mentioned (developers not familiar with the language, added complexity...).