charliehll:
What you mean to say is that the Rambam HELD that they didn’t exist, so maybe if you are Yemenite there is some protection for you.
Other Rishonim held differently though as we can see from the plethora of minhagim we have today involving sheidim.
The Rambam is not the only Rishon in Jewish history nor is he the only posek with an opinion on this.