I don't think you're work requires no creativity. But I think you have to explain why visual design that's experimentally shown to impair creative cognition is tolerated and even embraced by people in "left-brained" professions. My explanation is that people just have different needs. Not everyone needs high octane gas, and designers shouldn't assume that they do.

"Design for design sake" is just another way of saying you don't share the designer goals of engaging an audience and enhancing creative cognition. There's nothing wrong with that, people have different needs, so "good" means something different to a designer than it does to you.