Once again the old stale reply that no one needs it.
And just as you say many sell on a just-in-time basis, there are many that don’t.
Go to Inventory zero warning and vote it up. I believe it is an essential item for proper inventory control. It doesn’t have to stop you from invoicing or selling stock you don’t have and in some cases can no longer order, IT JUST HAS TO WARN YOU OF EXCEEDING STOCK ON HAND!!