@bluedolphin-- I had a bowl haircut for several years when I was about five or six years old. And it was cut by a hair stylist! So I agree with you that this haircut is not always done at home.
My parents changed my haircut after a few years simply because I have a small forehead. The bowl haircut had really long bangs and they were literally getting in the way of my sight. In fact, one day, I took a scissors at home and cut off half of my bangs. My parents asked me what happened and I told them I couldn't see. So although a bowl haircut is easy to do, it does require some maintenance because the bangs need to be trimmed regularly.