Day-mon, every Linux admin I've worked with, old and young, pronounces it that way too, so that's where I picked it up.

I've never heard of people deliberately pronouncing it like that to avoid offending Christians though, seems like an American take lol.

I thought that it was just an archaic spelling of the modern demon and an alternative pronunciation to clairify that the speaker is referring to a technical part of an OS, not making a joke about the spiritual nature of the machine lol.

It sounds cooler to say day-mon anyways IMO.