As a web dev / game dev, I do like the idea, but just playing devil's advocate: Wouldn't players just mine ore via a cron job and forget about the game? It seems like a "make numbers go up" type of game without any immersion.
Personally, when I'm in the mindset of playing that game, I can't help but come back to my bot every 30 minutes to see if it's performing well. When I see that it's doing something strange, I take notes and can't stop thinking about possible solutions.
When I'm not in the mood to play (i.e. analyze the bot or program more functionality), it does indeed sit there, but to me, that's no different than any other multiplayer game. :)
I do think that it takes a certain kind of leaderboard-chasing person to stay glued to it, though.