At least you're aware of the disconnect. Artists are the same. They reject commercial graphic artists, too.
If it makes you feel any better - writing for marketing takes much more consciousness of word usage and semantics that fiction does. A fiction writer may be forgiven for being vague or annoying in one or two spots if the story is good. The marketer that misuses a word or conveys a wrong image usually isn't.
So no - your job isn't like the average writer. It's a little harder.
Yes, I do know this but have decided going the traditional route would be better for me. I guess I just want to stick with what I already know and found to work although it's been a few decades, lol!