I am with ECU on this one... the higher quality glass ALLOWS you to make a more informed decision as it relates to whether or not to shoot at an animal.
With a clearer image, particularly in low light situations, it also allows you a HIGHER PROBABILITY of making a good shot - which increases the deer you take and reduces deer suffering from poorly placed shots.
Add the fact that you get some amount of satisfaction in just knowing you have superior glass and it seems to be a win / win situation. I will admit some amount of pride when someone looks at one of my rifles and says something like "nice glass"...
I have long felt that the scope should cost as much as the rifle, or more... I say put the money in the glass... as long as the rifle is capable of shooting well enough to be a keeper (which for me, is being able to shoot a 1" group at 100 yards, or very close to that).
If the rifle can not do that, it is not worth hunting with and therefore not worth any glass!
One argument is made - that this high end glass could create a scenario where someone would be more likely to make a near dark shot and shoot something other than their intended quarry (like another hunter, perhaps).
I argue the opposite... the glass allows to more clearly identify what you are about to shoot at - at least in my opinion.
I think that hunters that are predisposed to take shots that are dangerous are going to do so regardless of the equipment they have.
My .02 worth!