aside from the usual reasons not to have kids (labour hurts, kids put an end to your social life, you lose your sense of self and they're expensive), this book has a really insightful outlook (she's a psychoanalyst) on why children aren't great... not for you, not for themselves, not for anyone. it's completely un-PC, totally funny and scarily true.
just an inkling:
kids are insane polluters
kids are conformists
kids are capitalists
consider reading this book. it's really interesting!