Dr. Phil is making the point that commissions arent always consistent. Being an artist in the fandom and living off of commissions doesnt give you a 401k, health plan, you're not taking in account of state and federal taxes and so forth, what about disability (ya break your arm or cant do artwork for a while and short/long term disability covers that).

So its not just about making a living off making art for people, its having stable lifestyle and being prepared for it. Yes some artists can do it on their own, but not everyone can.

This being said, its better to have a stable job and also do art commissions, because then you have options for benefits and making money on the side is also nice