The whole culture of the Empire is very mechanized and anti-spiritual, which isn’t what you’d naturally expect from a faction led by a Force user, even an evil one.
I think even if the original intention wasn’t for a Force user to lead the Empire this still fits. Palpatine would want to propagandize the Force in a way that makes people dismissive of it so nobody has any hope that the Jedi will come to save the day.
I really don’t think I worded that well but I hope you get what I mean.