He has probably got a point. I bet dog behavior and child behavior in a household is closely correlated.
I spend time playing with my children, I listen to them, talk to them, set them reasonable boundaries, I read to them, love them I am consistent with what I expect from them and the penalties they receive if they misbehave. I spent time researching pre-schools and take an interest in the learning they do there. I know that my children are my responsibility 100% Generally we have a happy, calm, loving household where everyone is shown respect and exercises self discipline.
As a result we have happy, healthy, well behaved (most of the time) kids.
We now have a dog and he is coming into a happy calm household. I will take time to play with him, train him, exercise him, I will be consistent with expectations and corrections/rewards. I have enrolled him in puppy training classes that we will all go to together and am reading and researching on here and elsewhere. He has been vaccinated has a good diet, fully insured and given all the vet care he needs.
I'm no expert but I think we stand a good chance of raising a nice dog.
Compare that to households where kids are shut in rooms all day in front of the TV to take care of themselves, they are ignored most of the time then shouted at sworn at and beaten inconsistently for misbehavior. etc etc - that will be the same household that chains a dog in the yard, riddled with worms and fleas, poorly fed, not trained, no time spent socializing the only form of disapline, shouting and physical violence.
You can guess what the kids and the dog will be like.