It's hard to use functional paradigms without closures and first class functions. But, more importantly, I would say it's more about the mentality of API designers and java programmers.
I've once used high level functions in PHP in a real production environment and it caused so much political problems that I had to rewrite everything in an imperative style. Not that the code was badly written.. it's just a different style that not everyone is used to.
I'd totally agree with the mentality bit, but it's not hard (although it can be unwieldly) to write functional-style code in Java if you're disciplined.
Imperative programmers will write imperative Scala, too.
I've once used high level functions in PHP in a real production environment and it caused so much political problems that I had to rewrite everything in an imperative style. Not that the code was badly written.. it's just a different style that not everyone is used to.