If you're a real artist, you're an artist no matter what. I think it varies with retail. Some people probably do it for the cash and discount, others are seriously interested in make-up.

I think your writing may have offended her, because some people strongly identify themselves and quality make-up with MAC. While most MAC fans are sensible, a few get way into the fandom of the company. It's, I hate to say, kind of normal. I've seen the rabid fandom happen with most popular things (computers, TV shows, movies, actors, etc.)