For Scala and Haskell, it could just be pragmatic developers vs purist developers (to grossly generalize). There are people out there who want the absolute bes

For Scala and Haskell, it could just be pragmatic developers vs purist developers (to grossly generalize). There are people out there who want the absolute best language for a project, even if they don't already know it. Then there are those who would be annoyed at having to learn a new language and all its quirks to do something that Java could have done, even if it cost more in servers or requires more lines of code.