I don't think this is the issue. You could easily give each developer a Haskell module to flesh out, like:

    foo :: Foo -> (Bar -> Baz) -> Quux
    hello :: IO
    this :: Is -> Starting -> To Get -> Boring

Arguably the restrictions they are bound to are much stricter than with Java.

But anyway, I don't think most Java programmers really "get" OO. So OO is not the reason they use Java -- there is something else. Probably a lot of marketing from Sun; constantly hearing about "certification" and whatnot makes the managers happy.