What do you think of writing a story to fit a market?
That is, you find that a publication is looking for, e.g., stories about butterflies. You think "gee, I could write a story about butterflies" and proceed to do so.
As opposed to going through your already-written stories and finding one about butterflies, or writing the story first and then looking through the available markets for one that might be interested in it. For some reason the last approach seems, to be (widely regarded as) the "purest" of the three, is there anything to this or is that just a silly prejudice?
I don't write professionally, but I am a musician and so I think some of the same things apply.
I think you have to a combination of them all. On one hand you have to have your own voice, but you also have to be willing to do whatever the market wants if you want to make any money. There's a trade off. It's a fine line between selling your soul and making a living... and you have to try and balance it.