Most employers don't want you to be creative because they don't want you to work. If they wanted you to be creative, they would create an environment where you could thrive at work. A place where you could shut the door and have silence to get work done. A room where you could shut the door and collaborate when needed. No meetings allowed that can be summarized in an email. No rows of cubicles or open-plans allowed with built-in noise and distractions.
How is this not obvious?