it's usually not as simple as you're making it out to be, though. If you have a team of developers, most of whom are not familiar with Scala, and you force it upon them all, most of them are going to sit there struggling, writing non-idiomatic code, and it's frustrating for everyone involved. The code becomes unmaintainable. Realistically, most teams don't have the time to spend on this, and there are very few tangible advantages to such a drastic migration