I've go a few things to add. The idea that a larger population means a larger talent pool to is true to some extent, but is dependent on many social factors. If you assume those factors haven't changed more than our population has grown, then this idea certainly holds true. Although far from having thought of all of the social factors, the two that I think would be the biggest factors are how much social push there is for young folks to get into football, have the demographics of people that play football the groups that are growing and also whether the number of good football programs is growing or dimishing at the entry level. All of the factors, IMO, actually favor more talent in football; football has gained poplularity and the push to be in the NFL has grown, espceially since the decline of basketball, football caters to almost all demographics so this is a moot point, and the era of disappearing athletics in some high schools has only just begun and is not hitting the NFL yet.
There are also other factors that I believe have raised the talent pool; Pro and college football have gotten so big and so technical, that the shear number of trainers, scouts and coaches has gotten huge. I think this large pool of good scouts, coaches and trainers have become more sophisticated and have developed such strong, repeatable teaching methods that have trickled down to the high school. The age where people learn most and develop the limits of their potential is during adolesence, and with the fundamentals covered and some advanced concepts being introduced at this level, we are developing athletes with huge potential with the mental aspects of the game. I see no reason this trend shouldn't continue. (sorry, I can't resist any opportunity to use a double negative correctly in grammar
I think that the greater talent pool and the development of "smarter" players is contributing to the perception of the "not a good product" idea. I think it becomes harder for the freaks to dominate when the opponents are so talented and play such good technique. This disparity between the players make the game a bit more exciting for the masses. On the other hand, too much disparity would kill it. It's likely that the new PO rules are designed to counter this issue exactly and probably is making the game more exciting to the average NFL fan. This may even explain the seemingly disparity in officiating calls as well.
Injuries are probably the biggest factor in the "not a good product" idea. There are sooo many good skill and trench players hurt right now so that teams are really suffering right now. Goddell's stricter policies and longer suspension also contribure to this. I think it would be worth comparing # of injuries this year to the last 5, 10 and then 20. I'm pretty sure you'd find the number to be really high.
The high number of new coaches is also a factor. Changing coaches is sometimes necessary, but it happens far too frequently in the knee-jerk NFL. A 14-2 coach was fired last year. This kills consistencey and is a huge contributor to the mediocrity of today.
Although this trend might might lead one to believe there will be lower NFL ratings, it won't be much. The NFL has sooo many hard core fans, the media will contue to confuse the dummies with spins, smoke and mirrors, and the gradual sophistication of the football fanbase will insure ratings for a long time to come. Next year, if the Pats run the board (I'm still stunned that I can even say this), people will look back on this season and not think they had a "bad product", they will think about a team inducted as one of the best of all time... and they were lucky enough to see it.