It's not that wide. Besides, you're talking about the pathway to the natural, not the actual entrance to base
Oh and also, on maps like luna, when the mineral line of the natural is on the opposite side of a player's mainbase, it's a really easy target for mutas to hit the workers and retreat. Whereas on this map, the mainbase is right behind the mineral line so you can't really do that. It is quite annoying for non zerg players to have their natural constantly be attacked by hit-and-run mutas and not be able to strike at the mutas.