Collecting natural forest leaf mould

[Raybon]

I think it should be discouraged. One person to start and then more and more ..

If it's your forest then do what you like, but if it's not then hands off.
Leave only footprints. Take only memories. (And photos)

....but people haven't, have they? As far as I can tell. Unless it was on a huge scale I doubt it would seriously alter/deplete the environment.
Maybe one answer would be for Municipal Parks, who collect the stuff, to put it on offer for collection?