There’s nothing magical about the Terrible Towel. Magic isn’t real, and it’s a towel.
Still, people can believe what they want to believe as long as it isn’t hurting anyone else. It’s just sports. It’s supposed to be fun, and ascribing some sort of reverse voodoo to a piece of fabric, wherein anyone who disrespects it incurs certain destruction, is pretty funny.
It’s also anecdotally ... not false. This is a coincidence — the Steelers historically win games because they tend to be good — but bad things tend to happen after folks like Bengals running back Jeremy Hill who do stuff like this.