Not trying to be negative but this seems like some spinning of the numbers to reach that conclusion. I have to think the very pattern they are describing (casual hunters not buying a license every year) has probably been present for a least a generation or two.
From other studies I've seen the total number of hunters has remained relatievly steady over the last 20 years. Problem is the population is growing so the percentage of the population that actually hunts is dropping.
I don't believe upland hunting has fared well on either count. Much of that likely caused by upland bird numbers falling dramatically east of the Mississippi river where much of the population base lives.
The other premise of the article is a good one. There are approximately 7 million casual hunters out there. If the hunting culture could find a way to energize that group there would be a lot of positive benefits. Not the least of which would likely be non-hunters who could be "recruited" and fill the vacuum in the casual ranks.
-1pheas4