True, but what happens once the coal is a pile? Unless said pile is being turned into a giant bonfire it will need further transportation.

This means big machines and their operators. It means trucks, trains, barges, and yet more drivers.

Gas needs storage tanks and pipelines. Ignoring maintenance the entire chain from well head to plant can be automated. A trans-continental coal conveyor belt would look nice on a popular mechanic's cover page but would never compare to what already exists for natural gas.

Granted natural gas' infrastructure is capital intensive. Yet in exchange for this capital you get a transportation network that functions like a classic graph flow problem.