Don't have to be rich to own a plane. Almost anyone can do it if you can adapt your plane to your earnings. A C152 would not cost much more to own than new car per year. But most people want the new car, or the ATV, or the RV or the….
I own vintage Turbo Commander and am self employed in film business. It's probably at the upper end of my affordability, but it's important to me, so I forego other things for it. Drive an old car and live in smaller house etc. Some of the people I know of who own aircraft are:
Yak - Cameraman
Cherokee - Cameraman
Aerostar - Farmer
Arrow - Video playback
Turbo Commander - Airline Pilot
Turbo Commander - Winemaker
Turbo Commander - ex Wall St
Turbo Commander - Anesthesiologist
PC12 - Owns big syrup company
Citation 560 - Runs ice machine service company
C310 - Programmer
Twin Comanche - Sheriff
MU-2 - Electrical engineer
So, as you can see, they come from all walks of life. Even supposedly expensive turbines or twins are owned by people you wouldn't think necessarily would be able to afford it. Yet, they do.