The loss I've suffered is the loss of the right to attempt to sell your friend the file under the terms I want to set. I have the right to set those terms because I did the work of creating the artifact. You're completely allowed to find that a bizarre thing to protect, but you're not free to just declare that view the only reasonable one and expect no one to argue.

If I made my livelihood by designing homes, and I was good enough at that job that people demanded my services, then yes, copying one of my designs and distributing it without my consent is stealing something from me.

And I'm not conflating morally and legality. I'm really not. The two correlate pretty highly here (as most laws do for obvious reasons), so I guess maybe that's what's confusing you. But if I write a novel, and you put the original file on bittorrent, I created all the value here. You dragging a dropping a icon representing the bits on a hard drive isn't valuable work. And I believe that morally, the nearly infinitely greater amount of productive work I did to create that copy than what you did entitles me to more creative control. I believe that completely independently of whatever the legal system says. I also know that the legal system agrees with that determination and sets penalties for violating rules set up to enforce it. But I'm not using that as evidence for my moral position. It's not immoral because its illegal. The causation goes the other way around. It's illegal because the shared ethical framework of the people and society that drafted the constitution found it immoral.