it comes from the need to support java (which is of course also the language's great strength). see for example http://stackoverflow.com/questions/3689407/disa

it comes from the need to support java (which is of course also the language's great strength). see for example http://stackoverflow.com/questions/3689407/disadvantages-of-scala-type-system-versus-haskell http://stackoverflow.com/questions/3689407/disadvantages-of-... or http://programmers.stackexchange.com/questions/51245/what-kind-of-things-are-easy-in-haskell-and-hard-in-scala-and-vice-versa http://programmers.stackexchange.com/questions/51245/what-ki... - answers there discuss the tension between types and java (especially the long first answer in the second link).