I was thinking about possible ways to improve the mining functions in PS. It seems to me there are a couple of ways to make mining much more fun and they both involve being able to find artifacts or other loot while mining. There may be two good ways to implement this:
1) Have a small chance of finding buried artifacts and relics while doing regular mining tasks. I would think it would be a very very small chance, like 1 in 1000 times you mine. Just enough to surprise you and keep hope alive. When you did find something, it would be of considerable value and would make your day.
2) You could actually mine with the intent of finding artifacts. Sort of like an amateur archeologist or treasure hunter type person. (a la Indiana Jones) A good place to do this might be at the ruins. Again the chance of finding something might be smaller than regular mining, but the rewards would be greater to offset this. Balance it out.
In addition, the mining process might be changed to be more like the looting system, with a window that pops up with various finds in it, some valuable, others not so much. The gold ore, or whatever you are really looking for is in the list along with rubble, slag, sand, or soil, etc., and you would need to do the work of picking it out of the list so it lands in your inventory. It gets the miners more involved and makes them feel as if they are the ones actually doing it as opposed to mindless button-pushing. This also might make designing a mining bot more difficult.
The answer to the WHY? question: because mining is generally tedious, unengaging and too predictable.

edit: added illustration