After reading these posts I'd like to make a couple more observations. The spread or point limits some states use to limit buck harvest certainly have merit and are better than nothing. However, these kinds of restrictions can result in a bit of high-grading of your deer herd. Imagine if you told a forester to only cut the straghtest and limbfree trees in your woods. If you have a bunch of genetically supeiror young, straight and limb-free trees these might get cut under this protocol. If a young buck has great genetics (and nutrition) and grows antlers with 8 points and right to the ears (15 inch) this buck would be killed under every antler restriction regulation. So, in heavily hunted country with 6-point or 14-15" spread rules almost all such deer would be taken, even the great 1.5-2.5 year old deer. If the hunter can kill more than one buck they'll take even more of these super young bucks.
Another issue with antler restricitions are compliance. Some hunters may have difficulty determining if a deer is legal or not. Yes, we can count to 6 in Kentucky (even with our shoes on). But sometimes the decision is it a point, can you see the rack, etc. can make it tough on some. Same goes for spread restrictions. That's why in KY where we have these WMA 15" rules we also say this is a rack with an outside spread even with the spread of the ears. This gives the hunter a bit of way to estimate it. Although, the hunter can get in trouble by not taking in consideration the buck's "attitude". Imagine a deer in a relaxed condition looking right at you. The ear tips would be about 15" in our country. However, if that buck's posture was aggressive, the ears are laid back and narrowed in spread -- maybe only 10"'s wide! I wouldn't want to try to explain that one to the Warden.
Having written all this, we have some 15" minimum spread Wildlife Areas in KY (copied after some county-wide restrictions in Georgia). These spread rules work pretty well on these areas -- one produced 3 Booners in a single season.
Not all hunting regulations are decided purely for biological reasons. Perception, desires, and "politics" come into play sometimes. As long as the resource isn't negatively impacted, these are legimate factors to consider when making regulations.