Here is a hypothetical. You see someone on their iPad making a nice drawing. You then steal the iPad and then start making prints of that art and start selling them. To me the artist should be able to disallow such prints from being sold.

But your line of reasoning says that since the artist is unable to make money from the print, then there is nothing wrong with someone else doing so as the artist isn't missing out on any profit since they have no way to sell prints.