Everyone is paid to think.The notion that they aren’t is just a jerk throwing their power around and attempting to assert dominance and compliance. It sounds like in your scenario, it’s not that they are against thinking, but just wanted a different personality type.
Don’t discount the fact that people are biased against non-neurotypical folk. They probably had to say something, so they said “tentative” instead of “we don’t hire people like you.” It’s shitty, but pretty common for a customer service job.