To address this specifically, of course the multiverse has been around in sci-fi for forever, that being said it has a bigger degree of popular reception due to its presence in popular media. On the other hand it is not accepted as an element of fantasy, where it seems like it should be. I don’t think people like Sean carol are being specifically paid by the mouse to lie, because they wouldn’t need to. If he saw that it was to his benefit to promote the idea in order to support his more valid science work then why wouldn’t he? Think of Francis cricks book Life Itself, a book promoting the utter crap idea of panspermia. He has admitted he only wrote the book because it was present in popular media and would draw attention to him, and thus his valid science efforts. Of course the mouse isn’t giving scientists money to lie. They don’t have to, it can be a silent agreement that benefits both parties.