No, it is not okay (in the sense of being non-detrimental to one's terminal values) to like popular things simply on the basis that they are popular. Decision theories following this heuristic are vulnerable to numerous low-complexity attack vectors, leading them to (for example) perpetuate, generate, and incorrectly update on information cascades.
It would be more accurate to say that "Giving in to social pressure to have aesthetic preference on the basis of the popularity of such preferences has non-obvious and immodular benefits to one's terminal values, which are likely to outweigh their decision-theoretic vulnerabilities within human cultures."
Well, there are things this works for and things it doesn't.
For instance, you generally shouldn't decide whether to say God exists or not, or how to vote (beyond strategically), based on popularity. If enough people do that then we act collectively non-rationally and may end up in locally optimal but absolutely bad equilibria.
However, you should decide what side of the street to drive on, or what language to speak in your everyday life, based on popularity. These are simple coordination games.
What is music taste - or whatever else we have under discussion...
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.