Children DO give back.
A sleeping infant in your arms is the most peaceful feeling in the world - in a time when peace is in short supply, that is a valuable gift.
The new belly laugh of a three month old baby is a priceless gift, and makes the sleepless nights and dirty diapers much less burdensome.
When a crawling baby leaves a toy and comes grinning to YOU, because you are the best thing in the world, they've certainly given you something irreplaceable.
The toddler that tries to put the clothes in the hamper, and has to get EVERY. SINGLE. CORNER. inside, is just learning how to contribute meaningful effort, simply because they desire to please YOU.
It goes like that through their whole lives - their capacity to give grows as their need gradually decreases. And if you teach them, they begin helping with chores and their own upkeep around the house early on (yes, even the toddler trying to put clothes in the hamper), to the extent that the only effort a well-taught teen requires is encouragement, limits, and the car keys (which, as any parent of teens knows, gives you the ULTIMATE POWER over them, so it is worth giving them the keys a reasonable amount of the time!). By the time our kids are teens, we are in a sort of partnership with them for the function and management of the home.
As adults, they give back more than they take, though the overall exchange is less frequent.
My son. My oldest rebellious son, who in spite of his rebellion, always hugged me and said he missed me. Who, after Sidney died, listened to me cry out my grief on the phone with him one day. I said, "I feel so unpredictable. I can't even control my emotions. I cry over nothing now." and he replied, "MOM! It's not nothing! Your baby DIED!", putting into perspective for me that it wasn't the things around me making me cry, they were merely triggering a larger grief.
My daughter, who most of the time acts as though she cannot stand me (she has major mental issues due to Fetal Drug Effect), but who would still ask for a recipe, or call when she needed Mom.
My distractible third, the son with raging ADD, who served an honorable mission, and with whom I can discuss things of the heart, and know he will always get it.
My middle child, also a son, currently on a mission, struggling to find his place in the world, who writes his parents separately every week, and looks forward to our replies. Who does what he feels is right, even when he doesn't want to, and who talks of coming to work with our farm when he is off his mission.
The showgirl, the next child, in a selfish teenage stage, who still bakes cookies regularly for the family, and who will protest over any chore she does not choose, but helps with babies without a complaint, even the messy stuff, and who will voluntarily choose difficult chores.
Our quiet author girl, who makes our meals when I do not have the energy to cook (frequently now), who helps feed the animals and weed the garden, and does the dishes every night.
Our youngest son, dreamy and an avid reader, who prayed so hard for a younger brother or sister. The boy who took so much care when he had cancer, but who discusses spiritual concepts beyond his years, and whose love of history had him reading college level historical books by the age of seven. He milks the goats, processes the milk, and helps out so that I have time to work in our business and still get the rest I need right now.
Oh, yes. They give back.
And I wholeheartedly agree. 
) Whether someone wants to or doesn't want to have children is between themselves, their significant other, and - if they have beliefs similiar to mine - God.
