In addition to my prior post on the marketplace of ideas, here is another decidedly non-epistemic reason why some ideas are more successful as memes than others: I am thinking of the ease at which a person can say something (seemingly) smart for or against it. An idea with no epistemic value might still spread in the marketplace of ideas, merely because it is easy for people to debate on it, and to signal their intellectual abilities in doing so.
A prominent example is the irritatingly boring debate on ‘free will’. We could easily nip the philosophical discussion in the bud by examining the words ‘free’ and ‘will’ separately before we blindly bind them together. But that is not what we do. Instead of letting the idea die its well-deserved death, we feel the need to voice our opinion, to urge our arguments, and to thereby keep a bullshit idea occupying a place in the market of ideas.
It is certainly not the least charm of a theory that it is refutable; it is precisely thereby that it attracts the more subtle minds. It seems that the hundred-times-refuted theory of the ‘free will’ owes its persistence to this charm alone; some one is always appearing who feels himself strong enough to refute it. — Friedrich Nietzsche, Beyond Good and Evil, §18
This feeling of intellectual strength to refute (or defend) a theory is a major force in the marketplace of ideas, and one that, again, has nothing to do with the theory’s rational worth.