I think it depends upon the ages and number of children.
It sounds as though you have yet to experience some of the joys of parenting that many of us are currently living through.
Kids do weird unimaginable things, real wtf stuff, at the worst possible time.
I like to think of it this way...
Child no 1 wrote on the wall, I told her off sternly, cleaned and repainted the wall.
Child number 2 wrote on the wall, I told him off and cleaned it off, whilst dealing with the fact child 1 had become diabetic, trying to be a full time employee and run the household etc etc
Child number 3 wrote on the wall, I covered it with blackboard sticky back plastic and bought a selection of chalk pens and we all wrote on the wall, whilst number 2 also became diabetic, hid in a beanbag and ran around the house like the abominable snowman, filled babybell wrappers with shampoo and lined them up on his radiator to melt, I became a single parent, worked full time and attended therapy for rape trauma.
So yeah, I guess people are just child hating wankers who have no concept of what real life is like...no, wait...