I don't think that's true. Unless I'm missing something, I've really only seen that thrown around regularly since the Riviera. And I don't think anyone could say that it doesn't apply to the Riviera without being disingenuous.
I think people also misinterpret the meaning, though. It's not an attack on the quality of the hotel itself (there are plenty of Hyatt, Marriott, Sheraton, whatever that are very nice hotels); just a statement that it's relatively generic and void of the elaborate theming most Disney resorts rely on.