There is a tendency I observed in engineers to not want to appear dumb. This is a recipe for disaster when coupled with a deep language like Scala, because nobody wants to solve problems the simple way, and Scala gives a tremendous amount of rope. That's why I think it's only a suitable choice for very experienced or disciplined teams, with a strong consensus on style or any DSLs. I can see average enterprise shops lacking these things and ending up with suboptimal results if Scala is used.