They're helped by Deanna who seems to have bitterly resented being actively parented when she wanted to be left to vegetate. One cannot read Deanna's bill of particulars without realizing that she likes Elly for the same reasons we do not; one is left to wonder where Mira and Wilf went wrong that they gave birth to someone who admires and respects inattention, depression, rage and a willful inability to empathize with the needs of minors.
Speaking of the chronic stupidity and criminal ineptitude that passed for parenting in the Pattermanse, we find that the bellowing, inconsistency and lack of empathy have borne the bitter fruit of adults who cannot cope with the demands of daily life. Mike's first big decision, after all, was to run crying home to Mommy when the big meanie Gluttson asked that he try making one for a change. Similary, Liz's attempts at being a person in her own right were as pathetic, ugly and doomed as Elly's. The end result is that given that John and Elly make Mafia loansharks look caring and generous, the steps they take to make their children independent turn them into their clients.
What makes them look even worse is that the people they despise for their garish and unpleasant habit of enjoying their lives end up looking far more appealing to people who matter. As an example, when Elly puffs herself up by boasting that she gives Meredith and Robin time instead of toys, that really means that the children have a different person bellowing "Don't do that" without ever suggesting that there's something that they can do; the reason for that, of course, is that whoever's guarding them doesn't want to deal with them lest her brains dissolve and she become a weak, useless child herself. When I contrast her with Mira who gets involved and channels her children's creative urges instead of having the Pattersonian hope that they'll go away and reconcile themselves to their "proper" role of "grinning zombie who sits where Mommy plunks her down and never bothers Mommy by moving or embarrasses her by being curious about the world", I find myself thinking that Elly, Liz and Deanna are not only full of crap, they should be expressly forbidden from being near minor children. Steps must, you see, be taken to protect children from dangerous things and people.