it certainly can diminish the enjoyment
Right. I agree that this happens, but that's a fact about human psychology, as opposed to, say, decision theory or probability theory. There's no good reason that we should want it to happen this way.
And yeah, it wasn't a particularly deep post :)
I just downloaded the latest Radiohead album, and I love it.
Thinking back, I started listening to Radiohead years ago when I found out that some of the cool kids in school were into it. With all the hype about the new album, the status/fashion processors in my brain going to ensure that I enjoy listening to it. I would probably fail a double-blind test with a bunch of imitation bands' fake "new Radiohead albums".
But I'm really enjoying listening to the album, and that doesn't seem like a bad or contradictory thing at all, even in light of the statements above. If, hypothetically, I was enjoying it for purely non-fashion reasons, then presumably that enjoyment could also be traced back though a causal chain to facts about brain development, evolutionary psychology, or whatever. But we would have no problem accepting that enjoyment as A Good Thing since explaining enjoyment does not diminish it. And so it seems in this case.