I don't want children for the simple fact that I don't like children. Even if I came to like them after having them by accident, I wouldn't like them for a portion of their lives. I might treat them properly (feed them, clothe them, and such), but I wouldn't show them that I liked them because, well, I wouldn't.
If I were to change my mind about children, I would adopt. This is not negotiable. If my partner wouldn't agree, then no kids whatsoever.