the other thing to take into consideration with all of this is that the general rule in climbing is a knot reduces the breaking strength of rope by 50%. so if the rope is rate to 8000, and you tie a figure 8 pass thru to make a loop (or a simple overhand knot) you've just reduced the breaking strength of that rope.
that being said its impossible to climb without knots, junctions, carabiners, etc...so we all have to accept a certain amount risk. like others have said, I've hunted long enough to be around when the 'first' elavated stands where 2x8s or 2x12s with Vs cut in the ends that were jammed in the crotch of trees. no tether, no seat, a wing and prayer. would I ever do that again, hell no. but I also understand that everything we do in saddle hunting is 'mechanical' in some regards and all mechanisms fail. we just have to safeguard then best we can.
(heck, while setting a trail camera on monday a gust of wind kicked up that I would describe as moderate, and it knocked a widowmaker out of a tree 30 yards from me. I felt the ground shake when it hit.)