Well, he is being gaslighted by Gaston (well, Gaston is trying, but Maurice is too nice too notice,) so his credibility is already pretty low with the townspeople. Also, Gaston maxxed out his charisma. - Jennifer Dittrich

They think Belle's crazy too, though, and when she's like "here, I can prove it, because I have a magic mirror" they're all like "whoa, she's totally right." It doesn't seem like magic mirrors are lying around everywhere in that village. Why wouldn't they just think that inventor Maurice had invented something like that and freaked himself out with it? - Jandy

Heh, I think they all assumed that Maurice wasn't a good inventor so if a device actually worked, then it must be magic and not proficient engineering ;) - Victor Ganata

I dunno. It just seems like if you don't believe a beast can exist, you also wouldn't believe a magic mirror that shows you a beast would exist. - Jandy

I don't think they disbelieved that a beast could exist, but more that they believed Maurice was nutballs crazy. - Jennifer Dittrich

Yeah, if anyone besides Maurice had made wild fantastical claims, they probably would've totally believed them. - Victor Ganata