If a state has enough hunters to hunt six days, instead of seven, and get a decent harvest, the state can survive with a six day harvest.
Some states have too many hunters and a Sunday hunting day might only restrict a season, and make it shorter.
Some states with fewer hunters must open it up and get what hunters are available out hunting.

Every state is different. It is not a question of what is fair to the individual hunter. It's a question of how many deer can be harvested in that state.