Just as in anything, there are two approaches to writing. Yes, you can write for your target audience and try to make money. Or you can write what you love and know contentment.
But why is it assumed that the two approaches are opposing? What if, instead of imagining the middle-aged woman, I imagine a 34 year old man bored of the mainstream fantasy that followed the success of Harry Potter or Twilight?
Then I would be writing for the ideal audience, myself. I'm sure there are more like me, right?
Besides, we are writing fantasy. This is already a smaller market. If we wanted a wider audience range, we would write science fiction or romance.
Exactly - the two approaches don't have to oppose at all. We don't see them as opposing in our work. Do we see ourselves as storytellers, as artists? Yes. Are we writing for a target audience? Yes. We have a certain advantage in that we are our target audience - dark urban fantasy romance (a cross genre, btw) is particularly popular with women ages 25 - 49, which we are. So we write what we want to read and know we are hitting our target audience. Our beta readers confirm this theory.
So, yes, you can be "elitist" and still find commercial success. There is no reason why not.