I've heard, more than once, from rookie officials, that the non-shooters have to retreat to half court. I think this one (the myth) might be partly perpetuated by officials.
I know that I'm guilty of verbalizing "half court". Here's why: it's
much easier.
Sometimes you'll get a game where you'll make a T or INT call, and some player(s) do not know what to do. I've had them, and you probably have. Most of these the players figure it out soon enough.
However, that odd player that doesn't clue in right away... you could say to him "back up", or "move behind the 3-point line" (not accurate), or "move behind the 3-point line and above the free throw line extended" (which is accurate).
That one time every other year, "halfcourt, guys" works perfect. I admit that I have perpetuated this myth. Can I be forgiven?