AA paid the bills doing commercial work, my understanding is that his bread and butter account was a catalog, which for many photographers still holds true. Unless you have immediate success as an artist, or have enough money to sustain you, you will most likely use your best skills to support yourself. Often for a photographer that means doing commercial photography.
There is an up and downside to this, at least from my own experience. When I was in my teens my goal was to be an art photographer. I didn't have the need or desire to make a lot of money, I just wanted to do well enough to pay my bills and shoot what I liked. I assisted many photographers in my teen years and got a good technical background and made enough money to buy some modest gear. But then I started to get offers of magazine assignments, paychecks that would be 10-20 times what I was getting paid as an assistant (btw the more famous the photographer the less they paid). So at 19, while I was still assisting, I was also shooting assignments. This is a common situation when one is transitioning between assisting and assignment work. I'd be assisting some photographer on a magazine shoot, check my machine and find that I had an assignment the next week with the same magazine.
It got to a point where you are getting assignments often, and having to rent studios and drag all of your gear to a rental studio, set up with very little time, get the shoot done before overtime charges start and then pack it all up and get out. There was no room at all for a reshoot, no margin for error. Having to re-rent the studio to shoot it again could be a serious problem and it always looks bad when you are in a different rental studio every week.
Eventually you make the decision that in order to do the assignments efficiently and with the best quality you need a studio. Once you have that studio and the serious overhead that comes with it, you really focus on assignment work above all else because that overhead can become oppressive. So for the next 20 years, until I hit 40, I almost never picked up a camera unless someone was paying me. At 40 I came to that realization and decided to start shooting photos for myself. So in 1998 I made my first few tentative steps into B&W landscape photography. Four years later I retired from advertising photography completely.
I have mixed feelings about the years I spent shooting assignments instead of shooting my personal work. Part of me feels like the most productive period of my life is past me and that I have missed so many images that could have been meaningful. Another part of me feels that the extreme technical requirements in my commercial work made me a much better photographer and having worked with some excellent Ad's and designers added to my skills. And I probably would not have had the resources to equip myself as I have and to travel as much as I do if I hadn't spent 20 odd years focused on building a business. But I still wonder about the body of work that I never did. Anyway, that's my experience on the personal work v assignment conundrum.