>> Sure, you can use superstition as a slur for things you don’t believe in.
> I’m not dictating what the word means
That is precisely what you are doing by trying to insinuate that I am using a "slur". You do not have the authority to conjure a belief system out of thin air, assert that it is true without evidence, and start dictating to people the manner in which they are allowed to speak about it.