The list of reasons would be too long to get into. Sometimes I counter people with, "the only reasons we could think of to have kids would be to see if we could get a redhead (my husband's a redhead and I'm a carrier of the gene) and to get my in-laws to like me."
Neither of these seemed like good reasons to ACTUALLY reproduce. Although, I'm sure others have had babies for more trivial reasons. So, yeah, no kids for us