Regardless of the actual evidence or not of this claim, I would say that psychologically, many people are into the "classic", "old school", "original", "vintage", etc thing, so people will actually pay a little more just cuz it looks cooler to them. Also, "more features" doesn't necessarily mean "better bass" to any one particular person or situation.
Here's an analogy that kinda sums up what I'm saying- people will pay $4000 for a Fender custom shop P bass that isn't really functionally any different from their $2000 high end production models. But someone spends extra time making it LOOK old, relic'd, vintage, whatever. I can't imagine why anyone would pay such a premium for the LOOK of an old bass (I'd be especially ashamed that the wear wasn't "earned" over the years, so to speak), but they do. For $4000 there's a lot of other small custom bass luthier type instruments I'd buy instead, but some folks want a damn old looking p bass with the Fender logo on it. lol