The problem with sitcoms to me isn't that they're too idyllic, so much that they tend to have very low writing standards. Gag-driven writing, formula-driven stories, overuse of character gimmicks, leaning on well known standup comedy cliches which are hilarious when a guy says them into a mic for five minutes but tedious and stupid when characters act that way for half an hour.
I would also disagree with the notion that children doing whatever authority figures say should be called 'idyllic'. Children are supposed to establish their independence when they're teenagers. I've heard stories from one of my old bosses about a 26 year old employee who had his mother call him and say that he's been too hard on him. That's what happens if children never rebel against their parents. That's probably how the Full House kids ended up, completely relying on authority figures for all direction in life.
The period from about 12 to about 18 is the time period when children are supposed to transition from being dependent on their parents to being fully independent adults. Instead we force them to stay dependent until they're 18 then say "Well, you're an adult now! Time to be independent!" Then we wonder why so many college grads have trouble leaving the nest, or they immediately become drug addicted sex junkies the moment they arrive at college.
So, I'm totally in favor of having idyllic families. But let's base the ideal on how humans are really designed to behave, not some 50's-Protestant painting of it that denies that basic human desires even exist.