There are what seems like a ton of small airfields and general aviation craft in my area (upstate NY); this is in addition to actual airports (Albany, Stewart in Newburgh, etc.) for commercial passengers/cargo, and roads/rails for any conventional transport (i.e., it’s not like you need a plane to reach a remote village, like in Alaska).
What are all of the pilots in these little planes doing? Just having fun?
Having fun
Flight training
Skydiving
Short charter/business flights
Powerline inspection
Traffic reporting
Wildlife counting
Drug patrols
Towing banners
Light cargo
Aerial photography
Surveying
Transporting organs/patients
Everything Berkut said.
I would have gotten to this thread first, but I was out flying from my small, general aviation airport.
Why?
Sorry. Maybe this is verging on IMHO, mods. But I’m just fascinated and befuddled by the fact that I watched probably more than 60 planes an hour approach for landing here today (it was Sunday, and quite nice), and I can’t imagine why I would NEED a little plane. And maybe I’m crazy (not unlikely) but that seems like a lot for just flying lessons/fun.
And I know for a fact that there is no skydiving going on here, at least–that’s down in Gardiner, out of a different airport–so subtract one percent of your reasons 
Well, as Berkut said, it’s not all for fun.
Also, it may not have been as many planes at it seemed. Someone who actually knows what they’re talking may be able to confirm/deny this, but I’m fairly certain that a large part of flight training is learning how to take-off and land. I seem to recall that, when my sister was taking her lessons, she spent at least one lesson basically taking off, landing, and immediately taking off again.
Since when do we only do things we NEED to do? Do you need the computer you’re reading this on? How about your TV? Do you enjoy sports?
I fly airplanes mainly because it’s a hell of a lot of fun. That’s the only excuse I need, as long as I’m paying for it myself. But as others have pointed out, General Aviation is used for many, many things.
I had a client who gladly accepted the expense of a corporate airplane, which was kept at a small airport near headquarters.
It was 30 miles away from the nearest commercial airport, and 90 miles from the nearest airport with significant major airline service.
The company’s major clients were in Detroit, about 500 miles away. Even a slow direct flight would be at least halfway there by the time they could drive to the airport, clear security and get on a commercial flight. A lot of times they could leave early in the morning, conduct their business in one day and get back at a still-decent time that evening.
You don’t really want to keep a small plane at a major airport. Not only are the fees higher, but your small plane is just about always last in priority. Even our local TV news and traffic helicopters are based at smaller suburban airports.
The flip answer is … because I can.
As already pointed out, a number of them were probably the same plane practicing take-offs and landings. Even though I’m a number of years past being a student working on a license, I still occassionally spend time practicing take offs and landings. When I’m in the groove I can easily do 6-7 landings in an hour.
The money does add up, true - but there are people where I work who spend more on golf in a year than I do on the airplanes. For that matter, there’s a woman at my company who knits scarves with yarn that’s about $50-80 a skein, which also adds up rapidly. She spends as much money to knit one scarf as I do to fly over the course of a month.
Strictly speaking, I don’t need to fly, no - for me, personally, it really is something I do because I want to, not for any other reason. But how is that different than someone who spends money on a boat or a fancy car? I’m renting right now, but if I wanted to buy the airplane I most often fly it would be under $50,000 - less than a luxury car or SUV. The type of flying I do doesn’t require millions of dollars.
Some people golf. Some people scuba dive, or climb mountains, or go on safaris or hike across remote regions of the earth or sail solo across an ocean or surf. Some people ski or snowmobile or chase tornadoes. Some play poker in Las Vegas. I happen to fly small airplanes.
Why? Well, like I said - because I can. Because I love the feeling of accomplishment when I plan a trip and successfully complete it. Because I feel powerful and free at the controls of an airplane that’s a mile or two above the ground. Because for as long as people have been writing down their thoughts there has been a certain number of us who have longed to fly, and right now we happen to be living in a time when that’s possible (with a little mechanical assistance)
Before we completely dive into IMHO-GD territory, or, G-d forbid, Pit territory, you forgot a few, Berkut:
Search and rescue
Civil Air Patrol, the civilian wing of the USAF auxiliary.
“Why I Fly” at AOPA Online
One more: Because a hamburger just tastes better when it costs $100.
Let me ask the OP: What are all those sailboats down at the harbor for? Or all those motorcycles on the highway - isn’t a car safer? How about those ATV’s in the backwoods - what practical function do they serve? They’re just plain fun, dammit. Liberating. They form a feeling of community among their users. And, unlike them, GA airplanes often have far more useful functions they can serve (already listed) when you’re looking for a practical rationalization to a question like the OP’s.
I’ve always wanted to fly. Just wanted to for no need whatsoever. But now that I learned I could go to school for the big jets, I’ve kind of been wanting to do that. Stupid job gets in the way, though.
Seriously, though, it would be a killer hobby – no pun intended (I hope). Just to fly, and be in control of the aircraft, and do what I want to do in the aircraft (within the law).
IMHO ahoy!
Don’t *let * the stupid job get in the way. It doesn’t have to. A private license will cost you about USD6000 total, about half the cost of a good used car. A serious golf habit, as Broomstick pointed out, is more expensive than that. A Harley is, what, about USD20K? How about that sailboat? There are plenty of ways to go about it that won’t impinge on your lifestyle except to make you happier - look into Part 61 schools in the US instead of the more-rigid Part 141 ones, for instance.
I thought hard about it when I was younger, decided my interests were more in the engineering side than the flying side, and rationalized it away as too expensive. There were always bills to pay, other things to do, and I wasn’t having much fun. Finally a co-worker at my new place of employment, a CFI on the side, coaxed me into getting started (I’m using another engineer co-worker, also a CFI as is her husband, as my regular instructor because she’s on the payroll at the FBO - works great, we talk engineerese in to each other; drives the chief instructor nuts. On a nice afternoon, all it takes is for one of us to say “4QZ is free, this place sucks, let’s go”). The only thing I wish I’d done differently is to have started 20 years earlier. The things I wouldn’t have bought instead I wouldn’t have missed anyway. The family likes a happy Daddy too, btw - and he’ll be happier with first solo out of the way, coming very soon to an airport near you (SFM, for those of ya - unless Bush is in Kennebunkport again and the TFR expanding P67 is in force - local lore, every field has it).
If you want to give an airline career a try, you can’t wait much longer or the option will be foreclosed. Don’t spend the rest of your life regretting it.
I know someone who flies a Beechcraft, and he’s done a lot of his travelling in it.
He shows considerable satisfaction (the fun part) in the whole thing: doing the maintenance inspections and adjustments, keeping his flying up to the standards, tracking all the changes through AOPA (Aircraft Owners and Pilots Association), seeing the world from above, providing necessary information to the passenger (me) so I know what not to do and have the information to reduce fear, taking off and landing correctly, having a great deal of well-founded knowledge of weather, and all.
The local pilots were invaluable right after the Loma Prieta earthquake, when Watsonville seriously needed assistance, and transportation was a problem. That is one example of General Aviation being of value to society.
Uh-oh, why?
Age. Younger pilots, who can fly more years before reaching the mandatory retirement age of 60, are preferred by the airlines. It’s a highly competitive job market - an Airline Transport Pilot license is no guarantee of a job.