You do have a few cool, real-world products out there in Haskell (eg, git-annex, darcs). But to be fair, there is a fairly steep learning curve.
Once upon a time, at my old company, a guy came to an interview. He was very experienced in PHP, having used it to build websites as a freelancer for something like 10 years. Did he know object-oriented programming? He'd heard about it, it was probably good for larger teams. Because he'd just been working with the same techniques all these years. And the sad truth is, your average programmer is likely to be like this guy. In which case, you want to give him a solid language, which is aimed at preventing him from shooting off his own foot, and does not feature many complicated concepts, like Java.
Once upon a time, at my old company, a guy came to an interview. He was very experienced in PHP, having used it to build websites as a freelancer for something like 10 years. Did he know object-oriented programming? He'd heard about it, it was probably good for larger teams. Because he'd just been working with the same techniques all these years. And the sad truth is, your average programmer is likely to be like this guy. In which case, you want to give him a solid language, which is aimed at preventing him from shooting off his own foot, and does not feature many complicated concepts, like Java.