It’s actually quite simple. If I steal your car, I have your car and you don’t. If I clone your car, you still have your car. Theft leaves you poorer, copying doesn’t.

Now, there is a valid cargument about me having some benefit from some vehicle designers’ IP without having paid for it, but it is not necessarily true that if I couldn’t clone it I would definitely have bought it. So the clone cannot be considered a proven lost sale.

The law actually supports this. Nobody has ever been prosecuted for piracy under the laws of theft (except back in the day when piracy actually was theft, shiver me timbers and all that sort of stuff). It’s always copyright violation, and in sensible countries the prosecution have to prove there has been substantial material loss to the IP owner, which in the case of single copies for personal use is virtually impossible (especially where we all have to pay a blank media tax which compensates copyright owners for copies that might be made, even where those media are not used for copying someone else’s IP, which is scandalous, but here we are), but where someone has cloned stuff and gone on to either sell copies of ther clones that’s a lot easier.