MW13, Yes, clearly the Rambam is lsheetoso. If he believes sheidim don’t exist, then the only way he can explain those gemaros is to say they are not-literal.
HaLeiVi, the Rambam says in Hilchos Avodah Zara that Ov and Yidoni were illusions and not real.
I will now say something which may upset some people, but please consider with an open mind. Possibly the belief in demons was a fear that people had in earlier times. Before people began to understand that disease was caused by germs, genetics or other natural causes, possibly it was common that great fear of unknown or supernatural beings existed because they were thought to be a cause. (Of course Hashem runs the show, but we now believe He does that in a natural, rather than supernatural way.)
I had occasion to look at the Encyclopedia Judaica under Demonology today, and there is a fascinating article on the topic. The writer collected from gemaras, psukim and many other sources (before the internet existed). What disturbs me is that many of the non-Jewish demons had the same names as the Jewish ones. So some of this may have been a pervasive belief or fear in ancient times. I find it troubling that these concepts have entered Yiddishkeit when they seem like Avoda Zara, and pagan beliefs. Don’t frum Jews believe that Hashem runs the show, period?
To amplify my earlier objection in previous posts, a (morbid) mashal is for example when we appeal for clemency of someone accused of a capital crime. Nobody tracks down the name of the executioner, say Mr. John Doe, and then writes a letter to the authorities saying please protect me from this horrible man, John Doe. Rather, one writes to the Governor and says, please commute the sentence of so and so. John Doe only does what he has been ordered to do. And if John Doe is off-duty that day, they have other executioners available. John Doe is not in charge of anything and has no say in the matter, and he does not affect the outcome in any way.
Why do we get involved at all with these supposed supernatural creatures, and not just daven to the RBSH?