If I add a handler, I use:
If I want to remove it, I usually use the cheap way out since I still haven't learned to do it properly (I was young and I needed the money):
Usable hack on a remote island but if by chance any addon or script uses the same handler, then disaster ensues.
Now, with drivers it's so much easier for this addled brain of mine:
bpy.app.driver_namespace['curtis'] = captainFuture
Nothing to remember but a string and a location.
Is there a binding reason why both approaches are different? Or asked differently and selfishly: Why not use dictionaries all the time?