People work in equally dangerous professions elsewhere for less, they knew the risks when they took the job. /shrug

I wouldn't trust a preprogrammed robot to dig me out, wireless controls would reach their limits fairly quickly without humans placing relays in the mine shaft, and wired controls would have a host of problems within the mine shaft as well. It honestly isn't really feasible from a business standpoint, especially with how rare mine collapses are in the first place.

It'd likely be cheaper to pay for the labor and possible death benefits, from a purely business standpoint.