Not to disagree too much, but it could be those 12-14"ers are still short on age (ie below that stated in the OP) to really express themselves.I think it would be possible to select for smaller bucks, but right now I don't think there are enough selective hunters out there to have an effect. The vast majority of tags are filled in the first 2-3 days of the season, on average 12-14" bucks. Dominant bucks are probably the ones getting picked off...the ones that are highly visible, running all over hell, getting themselves in trouble. Subordinate bucks are likely by themselves and less visible.
Then again, really big bucks are few and far between (thinking WY...not NM or AZ). Maybe it wouldn't take many selective hunters to have an effect.....
IIRC, this is exactly why there are herds of elephants that are showing a high propensity for being tuskless. Tusks got 'em shot for years.
I find the 'mind bender' part of this that goes against what we all "know" regarding large animals to be pretty cool.