I am a big advocate of the short bow. The old 48" Bear's gave the whole concept a bad rap. Todays short bow, with proper limb design, does not pinch even out to some extreme draw lengths.
As far the need for a short bow....I hunt Michigan. Thick, brushy, Michigan. I appreciate the shorter limbs when in a ground blind, but I think they really shine in a treestand. My favorite set up in a tree, when I can find it, is in a nice thick gnarly pine. The less I have to trim the better.
I do understand the beauty and smooth shooting of a full sized long bow (or recurve, for that matter). But for me, I just don't see any difference on the target. Keep in mind, I'm not shooting tournaments, either.
As far as the light rifle comparison, I agree that the weight of a full sized rifle will help you hold on target much better. My favorite flintlock weighs 12 pounds....I just don't see the weight making that much difference in bows measured in ounces. Again, thats MY opinion. There are much better shooters on here than me, who can prove that theory otherwise.