I care about them because they add more replayability to games. I would have stopped playing tables like Genie and Black Knight if it weren't for trying to get the trophy for completing all goals.
That's kind of false "replayability" though. If you would have stopped playing those tables, then it means you don't like them. Which means you're forcing yourself to play them just for the trophies, and honestly, that's kind of silly. That's not true replay value. You have to be enjoying it, replaying the game for fun's sake in order for the "value" to kick in. Because the "value" in video games comes from how much fun we get out of them, because yes, that's the point of playing games in the first place. If you're merely a trophy hunter, just say so, it's alright. You don't have to fabricate phony "reasons" to justify their existence.