I contemplated a response to this thread for a couple days, as my thoughts on this topic are complex.
I learned hunting late... my family didn't hunt, but I was hugely interested from reading magazines and was taken on my first hunt in 6th grade. By graduation from high school, I was regularly duck, deer, and hog hunting with friends.
We cut our teeth on public land, as private land in central, east coat Florida seemed to be out of reach unless you were a blood relative. I learned to hike farther than anyone else to get to "untouched" areas... cross gator infested swamps in the process... hunt only the quota hunts for archery and modern gun. But beyond those week-long periods, I avoided the WMAs like the plague as the yahoos would descend in a sea of orange and it just wasn't worth the hassle. After joining the Air Force after college, my friends eventually gave up hunting the regular WMA we used as the cost in stolen stands, confrontations in the woods, and reports of people having their vehicles shot up in the remote areas we frequented made the risk seem too much. Add to that the low deer population, and it was a much celebrated event if any of us took a deer. Hogs were more common and our staple for hunting. The risk/benefit was not there.
Since then, it seems we as a society devolved to respect each other and each other's property even less. You hear it on this board from the landowners in Texas and other places defending their right not to allow any yahoo on their property to hunt, despite taking crop losses from hogs. Dirtbags shooting up landowners equipment, cattle, leaving fences open, etc is what their benevolence is greeted with. I've heard it first hand from farmers where I've been stationed, how they confronted strangers on their own property who claimed to have permission to hunt from Joe Bagadonuts. Problem is, Joe is not the landowner, and although the landowner gave Joe permission, Joe certainly did not have the right to extend that to others and give them copies of the gate key! In this case, the landowner was treated like a trespasser on his own property by the guy who didn't have legal permission to start with.
Also impacting access are companies like Base Camp Leasing. Private land that could have been available to the average Joe is now tied up in leases beyond the cost of most of the hunting demographic or going unhunted because the markup was too much. I perused these sites for the last 2 bases I was stationed and the costs were ludicrous. $3K/year for 60 acres and 1/2 of it flooded during heavy rains? $9K for 1 week of access to 1K acres? Uh, no thank you.
A local friend where I am currently stationed sought and received permission to hunt a section of land next to a major road last year. There was only about 15 acres of hardwoods in one square, right on the road, the rest of the 100+ acres was beans. He shot a monster buck on there with his bow. Fast forward and someone cued in the landowner to one of these sites. This year when he went back to obtain permission for the new season, they asked for some big $ for hunting permission. He couldn't afford it. All of that money really only got you 15 acres of huntable area!
The stories continue to get worse on public land every year. Stolen game cameras, stands, people using others stands defiantly... A coworker showed me a thread on a local hunting forum whereby posters were declaring that if you leave a game camera or stand in the woods more than 30 days, its public property and they would take it. State law certainly does not support that. But the number of folks who feel justified in that thought abounded on that board. Scary! What makes them think they have the right to take something they did not pay for just because its in the woods beyond an arbitrary timeline they unilaterally determined? It's not like good stands are that cheap! Thieves!
The industry has also warped what success in the field looks like. If you watch the hunting shows and read the hunting rags, you are a failure if you're not shooting B&C bucks! I must be some type of deviant because I am just as happy putting that 3 year old dry doe down as I would be shooting a buck, maybe even more so because I know the meat will be better. I was overjoyed when a friend invited me to Texas to cull hunt some does and spikes off their land a few years ago. Took my oldest down there and got her on her first deer. The fact it was a spike made absolutely no difference. We joyfully trimmed some older does and spikes and loved every minute of it and showed our extreme gratitude to my friend's family. By the industry standard, though, we must certainly be crazed for taking those does and spikes/forks!
The older I've become, the less time I have to hunt/fish. Pre-kids, wife, USAF: in college I bet I spent 2-3 days a week either fishing or hunting. Part of that is why I earned 2.45 GPA on my undergrad!
Now I'm a father and still on active duty, and my time away from work to spend with the kids and fish/hunt is limited. I don't have the time to deal in the nonsense of having gear stolen, confronting jackwagons in my stands, etc. Not to mention, I want my kids to learn this sport in safety, and not in a sea of orange. I am blessed that I have private land to hunt on, and have taken all of the kids to the woods now for the last 2 seasons. However, when I did not have private access, I simply did not go. Too much hassle, safety concerns, and too little time.
I am not alone in this thought process. This sentiment is echoed by the majority of hunting folks I talk to on my base.
So although the numbers are declining, is that really the root cause, or just a symptom? We can talk the video game generation, but my kids are online and play games, but when the boat comes out or the camo and guns come out, they are arguing over who gets to go with Dad this time. I don't think that is the problem!
I hypothesize that the real problem is multifold: overhunted public land, lack of accessible private land, lack of respect for private property resulting in reduced private land access, a warped definition of success, lack of respect for others hunting public land... Add all this up, and who wants to bother with it!