Which came first, necessity or profitability? What will you concern yourself with first if faced with a survival situation? Shikata ga nai, there is no other way. Sure, profit might come of your efforts, but the purest spirit of invention, in my opinion, does not begin with "what's in it for me?"
I am probably inviting some sort of debate here, but I feel compelled to share my feelings about Lith's idea that ultimately what drives people to create is profit. Unless you're from Ferenginar, the entire universe cannot be explained within the context of the marketplace.
I'm sorry, no. Speaking as a creative person, I know I make stuff up all the time which has absolutely zero potential for profit. I wasn't thinking of profit when I made whatever it is up-- in fact, many of my creative efforts (including probably spending the time to do this writeup) actually rob me of profit, as I am doing them instead of something where I could be selling my time.
Nonetheless, these efforts are necessary in some way. My existence was lacking in some real, non-abstract way. I invent something in an attempt to fill that void. I may succeed, I may not. If I succeed, I may profit from it. That's invention, and necessity, as you see, was the Mother of it. But Profit is an abstraction, an artificial means to simplify the workings of the world into a quantifiable system. It is an end, not a beginning.
Furthermore, I would suggest that the idea of profit doesn't take into account intrinsic value. Even the most flawed, pointless effort is in the path of my lifeline and thus contributing to who I am and how I see the world. I grow because I have bothered to outline my idea in this writeup, I grow by attempting to create some pointless monstrosity with epoxy, Legos, and tie-wraps. Is that profit? Such things have an unquantifiable value which cannot be traded.
However, they are worthwhile nontheless. People who inisit on excluding this from their worldview and focusing only on what can be traded and acquired are the same people who lack appreciation for truth, beauty, and wonder. They ignore the value of such things, focusing on what can be bought and sold. But, simply because our culture finds it easy to pervert a creative act into a commodity does not make the commmodity and the act the same thing.