How come there has never been a retired referee as an announcer?

[CRedskinsRule]

Originally Posted by Alvin Walton

Has there ever been one?
I always thought that a ref could give a lot of remarkable insight into game.
Imagine Jerry Markbreit or someone like that in the booth giving color commentary.
I wonder if the NFL frowns on that sort of thing.

Well FOX does have Mike Perirea(sp?) as an on call personality. He offers some good insights but not really anything super fascinating.