Ah jeez its almost like art inherently has nothing to do with business
well if you do art in a professional setting it shows that you're reliable and know what you're doing. if you do it as a hobby you aren't a real artist, you're just someone who happens to be good at art and does it for fun.
its like if i said 'im a programmer' or 'im a game designer/developer' even though i'm clearly not. i've been scripting for 8 years and i know java and C# enough to program in them, but i'm far from being a programmer. i dont work in a professional setting so i dont understand the various industry techniques and i have no idea how to communicate between other programmers to form a cohesive program that is both readable, flexible and functional.
when you do something professionally you have a full understanding of almost every aspect of it, and understand how you can adapt and change your art style so that it can improve. if you're a hobbyist, you're a hobbyist.