What about religious people who take vows of celibacy?

I think people care more about self-preservation than reproduction, honestly. I know I do!

Edit: Upon reflection, and receiving some replies here, I actually think Tim made a pretty strong case. However, though "playing chess" may be the "single most helpful simple way to understand" Deep Blue's behavior, it is wrong to say this of "trying to reproduce" for human behavior. You could predict only a very small percentage of my behavior using that information (I've never kissed a girl or had sex, despite wanting to) - whereas, using "self-preservation" and "seeking novelty", you could predict quite a bit of it. I suspect this is not just true of me, but of many people.

Edit 2: Though you could poke holes in my first edit. Like, maybe the reason I don't try to reproduce now is only because I've failed in the past. But this hinges on being a violation of Tim's point. Also, see this later comment I made, which I think is pretty much a knockdown refutation.

Edit 3: See this comment by memoridem for a succinct summary of my position. Somehow, none of my comments in this conversation came out clearly.