Or because they realize that it's not as much fun to work with deadlines and someone else's vision and it doesn't pay very well.
There is a reason the stereotype is called the "starving artist."
This is an overlooked argument. Art is wonderful, it should be encouraged and embraced. Just because you have a talent though doesn’t mean you must use it. I had a particular talent for something that I loved to do when I was younger. People always asked why I didn’t pursue it professionally. It was simple- I was good at it, it paid well (if you made it), and I loved doing it. That was the key. I loved doing it for me, my way, when I wanted to. Knowing that my livelihood dependended on it, having to get up and do it every day wether I wanted to or not, having to do all the networking and training and keeping on top to be a pro at it- I wasn’t interested. It would take something I loved and make it... a job. So yes, as we age we may loose passion for what we once loved, or we may simply realize we want other things more and having both is too mucor impossible. We may just not want to take something that relaxes us and turn it into another source of stress.
Our daughter is really into art and we explained to her if she really wants a career in art she needs to find her field and work in that direction and never stop. She is leaning towards anime comic art. I explained to her she could write and draw her own mangas there is American writers for those or she could just work for other peoples mangas. She also wants to be a teacher she was super excited that she could be a teacher while trying to be a manga artist lol.
There is a reason the stereotype is called the "starving artist."