Consistency is also the reason why Java or C# are so popular for large system. I asked a Scala developer recently why does his company use Java but not Scala, d

Consistency is also the reason why Java or C# are so popular for large system. I asked a Scala developer recently why does his company use Java but not Scala, despite their developer's familiarity with the latter. He answered that while Scala is fine for small teams, when we have 100 or more developers there will be factions (scalaz, cats etc...), and it's very hard to maintain consistency between systems. With Java there is only one true style so it's easy to scale with larger number of developers.