Good points by both guys. Another reason for single pin is that as your eyes get older (I'm 68) and bows get faster the pins are closer together and just become a rainbow, and I can't differentiate one from the other. So for me it's single pin sights. Even when I used multi-pin sights I only used 2 pins (20 & 30).
So I'd have to say that a good hunting sight is one that you like and one you can see. Afterall, a pin is a pin.