Regulation
The issue for me is not so much the fatigue element (bad though it is) but the fact that standards in GH are largely voluntary.
Can anyone explain why, when pilots, cabin crew, ATCOs and engineers are licensed, GH workers are not? Ground damage is one of the biggest areas of operating costs for most airlines, and ramp workers are killed and injured with monotonous regularity across the globe. So why isn't the activity regulated like the rest of the chain?
There is an ICAO panel running on the topic but the result is likely to be watered down to mere compliance with ISAGO or similar, because the GHAs don't want to be regulated.