I guess it comes down to "Shoot the Highest weight you can draw comfortably"......if you CAN draw a certain weight easily then why lower your performance by shooting a lower weight just to shoot a lower weight.
I know in a perfect world you may not need the extra 10 or 20#'s of draw weight, but shoulder blades, spines, and ribs aren't really a perfect world.......
I shoot 70#'s on all my hunting bows because that's what I feel comfortable with......bonus that I'm getting some extra usable energy.
If you can draw a certain weight in odd positions, cold, under pressure and hold on target for a minute or 2 if you have to, then by all means that's the weight to be shooting.
Don't handicap yourself because you "Probably don't REALLY need it".

Lightweight bows can handle whitetails quite effectively. But, if you can handle more draw weight without a loss in accuracy, you have the primary advantage of being able to shoot a heavier arrow for more penetration and the secondary advantage of getting a flatter trajectory. My own bow this season draws 65# @ my 25" draw. I have two sets of arrows...620 grain primary hunting arrows and 800 grain engine block tamers that I plan to use when hunting in close quarters. I have other bows I may switch hit with that draw 70# and 60#...depending on how cold it gets. :^)