One of the fun pastimes I entertain with friends (read: arguments I like having) is arguing about the definitions of words with subtle shades of meaning between them. At some point along the way, one such discussion turned to the meaning of the word fantasy — in the most generic sense of the word, one broad enough to mean things like a Playboy centerfold, not one limited merely to books by Tolkien / C.S. Lewis / Eddings / GRRM / et al — and about what classified as a "harmless" vs. a "harmful" fantasy. The general consensus was that any fantasy you could not act on without such action being expressed primarily and solely as the infliction of harm upon another sentient being was bad news.
I love it when discussions like this come up, because they afford all sorts of digressions that might never come up otherwise. So, my riff on the whole thing went like this: The agreed-upon definition here presumes that the person having the fantasy wants the fantasy to come real in the first place. But many fantasies are not like that — and in fact, I'd argue the vast majority of fantasies are not like that. That's why they're fantasies and not aspirations (to pick another word that might better fit that specific bill).
Most fantasies are designed to be left as fantasy, because the minute they're made real, they're also made mundane, flawed, limited, and susceptible to all the corrupting ways of the world. As long as they're not realized, they're forever perfect, in the same way our ideas about the perfect date are likely to be far better than whatever the real thing turns out to be. They're better because they never have to be made real. They can be nothing more than pure desire, which makes them inherently unrealizable and eternally unsatisfiable. (You can never satisfy a desire in the abstract, only its most immediate incarnation, in the same way eating a meal only abates your hunger right now and not perpetually.)
OK, now let's go another step past that. You know the old adage about giving the people what they want; let's apply it here. What happens if you satisfy people's fantasies whether or not they want them to come true in the first place — especially if they're not even sure if they want them to come true or not in the first place? Is it wise to give people what they want, when what they want might be something that ends up debasing both the recipient and the giver? Or when they themselves might not even be sure about what they want in the first place? (To wit: an example of such a discussion from the video game side of things.)
You might well guess this is my way of leading back into my perennial discussion of authors trying too hard to please their fans, etc. And it is, although this time around I want to expand the discussion of that subject a bit; no sense in me repeating myself.
Most folks are not creators, but rather consume the creative works of others. The balance on this may have shifted as of late — see: fanfiction, et al. — but I'd still wager the vast majority of people are still best described as being the audience rather than the artist. To that end, the audience-members have somewhat less of a sense of what's involved when creative choices are made — mainly, why it's not always a good idea to give an audience what it thinks it wants. Creators know how such things, when indulged in, often have the same ghastly trajectory as any other untouchable fantasy brought to life: what seems like a good idea when bandied around between friends over drinks, augurs nosefirst into the dirt when made real.
The thing is, every audience member is also a potential creator. All that separates them from being a creator is, well, creating stuff and getting it in front of an audience. And I'd wager that a key thing that separates creators from audience members — aside from lots of hard work — is not just the fact that they create but their own attitude towards their creations as far as their audience goes. If they see themselves as primarily being a mirror of their audience's desires, they're going to end up with a markedly different flavor to their work than those who are driven to do their own thing, even if it means giving audiences what they deserve (in the creator's eye, anyway) and not what they ask for.
This isn't me saying the audience-pleaser contingent like, say, Jim Butcher (utterly arbitrary example) is an inferior breed of creator. I'm trying to avoid the idea of a ranking system here, with all of its attendant snobbery. But I am saying that any creator needs to confront this issue at least once in their career lest they miss out. For some people, giving their audience exactly what they say they want is more than enough; for others, settling for that may only keep them from knowing a far greater kind of satisfaction.