1. The money those people might have paid was all theoretical; it didn't belong to me and wasn't even promised to me, so I haven't lost it in any greater sense than I "lose" $100 million when the numbers on my PowerBall ticket don't get drawn.
Then if I blow up your car, your damages are all theoretical. Maybe it would have broken down and cost more to repair than it was worth. Maybe you would never have sold it.
2. If we consider this an actionable harm, then we must also include everything else that diminishes the resale value of my Rembrandt. Maybe a stash of new Rembrandts floods the market, or a new biography comes out that proves Rembrandt was a horrible person so no one wants his paintings, or a new biography comes out that proves I'm a horrible person so no one wants to trade with me. All of these diminish the price I can get for my Rembrandt, so I guess we have to outlaw those as well?
As I quite clearly said, their has to be a wrongful act and the harm has to be fairly traceable to a wrongful act. Of course it is perfectly legitimate to "kill with legal blows".
Suppose this happens:
1) I write a novel and have a contract to sell it.
2) You break into my house, open my safe, and copy the novel. You post it on the Internet.
3) My publisher cancels the contract.
You would have to argue that my harm is not fairly traceable to your wrongful act. That's utterly absurd. It's just as traceable as if I had a contract to sell a painting and you defaced it.