Unpopular opinion: Using a standard post hole digger for every job in rocky soil is a waste of time and muscle.
After a brutal week installing a 150-foot line in Boulder, I switched to a manual rock bar for the first 3 inches and saved myself hours of frustration, so why do so many crews still just muscle through with the wrong tool?
You're right about the rock bar, but the real issue is training. A lot of crew leads learned one way and just pass that down. They see switching tools as slowing down, not speeding up. It's a stubborn mindset that costs more in labor and wear on the guys than buying the right bar would.