Because that copy was already sold, and the artist already received their cut of the profits (however tiny). They're not entitled to any percent of resales, so there's no reason to be in contact with them.

Bootlegging is not the same as reselling. Especially since we're talking about digital music here. Something that can be copied exactly for free. This isn't even like someone painting a forgery, which would at least be a distinct piece of art. That would be more like if an artist recorded a cover of an entire album (and then claimed it as their own, which is where it becomes problematic imo. Just covering the album would be fine if they give credit to the original artist).

I've got tons of issues with how our current copyright system is set up, but so many people seem to want to throw the baby out with the bathwater.

There should be some protections for the people creating the actual artwork. It's ethically wrong to take someone else's artwork and sell it as your own without permission. It's insane that this even needs to be said.