They're not going to join the crew, after all
But they already are. They're as much a part of the "crew" as the flight attendants or dispatchers.
You're right though: Who knows what type information they can give you, if any.
But I know of one IFR controller in my area who is an ex-airline pilot...he can hold a Class 2 Medical but not the Class 1...so why don't I think he could bring me something over his 10,000 or so hours in the air?