Lets theorize about a food replicator that can only copy food, it can not create new food. Kind of like a copying machine, it cant create new pages with text on them, only copy pages that already have text on them.
So if you were a grocer and you sold food, people could come in and make copies of the food in your store without paying anything.
By your analogy that should be perfectly legal, they haven't stole anything, you still have the food in your store.
How long would you be in business if you never sold anything? Why would you stock anything if it did not sell?
A physical is object is easy to comprehend, even a child can understand. Digital and the ability to easily copy something is a tougher concept. You are not stealing and object, just removing the potential to make money from an object. It is a poor business model to make products for free.