My own view is that it's a fetish, much like any other, and that it is very strong. I don't suppose that anybody makes single decision at any point in time to suddenly acquire some fetish (like... say... feet). But I don't think people are born with intact fetishes either. I think it's the result of a long process of both conscious and unconscious conditioning of the mind, over a lifetime.
It's not that people "choose" to favor boobs and some favor butts. Or that anyone "chooses" to be into bondage or whatever else turns them on. But over time, those things have developed and formed into a set of preferences. And fetishes do evolve over time, and can diminish in favor of something totally different.
Your pov makes sense to me.