I have to admit that I wrestle from time to time in my own mind the idea of hunting the biggest and the best. Like you said, in a predator/prey relationship, the predator usually takes the small and the weak. What we as humans tend to do is just the opposite.
I am kind of new to hunting (about 8 years and only have shot 3 deer) so that probably affects some of my thinking. I have no problem with shooting the first doe or fawn I see. I've never had the opportunity to take a mature buck, but I hope someday I do. (Ok, I saw the biggest 10 point I have ever seen while hunting standing 30 yards broadside earlier this year. No shot. Special MLhunt and I only had an antlerless tag. DOH!

) My first deer was a year and a half old buck, but since that time, I have let all the small bucks I see get a free pass. I guess I let the little bucks walk because 1.) I love seeing big bucks in the woods and you can't see them grow up if you shoot them and 2.) I respect the trophy hunters out there that do want to preferentially harvest a mature buck even though that is not where I am at. For those reasons I let the little bucks alone. Shooting a deer is not so important to me that I can't let a small buck go by. Does and fawns (even button bucks) get no preferential treatment. The little ones sure are good eating. Our season is late enough that at least there are no spots on the fawns.
You have some really good thoughts kev and they are ones that I have thought about a lot. I do think it is mostly about the hunt, but I willsay that since I started all this crazy nonsense at age 38

,getting a successful shot on a deer is still a challenge for me and the ultimate goal. I guess I'm still evolving as a hunter so my opinions may change over the years. I think that is pretty natural.
Good post!