it is, like tarot and other methods of divination, a way to cast an externally dictated framing on empirical situations and thus force oneself to reconsider one's biases. personally, i don't know anyone who actually thinks the positions of the planets materially affect outcomes
Don't take anyone's words at face value; trust but verify. Like, I get where you're coming from - obviously one has to be self aware and not actually stereotype people based on their birthday - but I think it's largely harmless.