The source of this madness, I should think, is that they hate having to admit that they don't really know what they're doing with their lives. Given how vain they are, how much they fear being laughed at and especially how they can't seem to ever to follow Porky Pine's advice to not take life so serious 'cause it ain't hohows permanent, it seems to me that, as I've said all too often, that they believe that if they're revealed to be ignorant, they won't ever be allowed to be taken seriously ever.
We therefore must contend with a group of numbskulls who, in the course of not admitting that they're in the wrong and thus being turned into a clan of pathetic zeroes who can only be laughed at, turn their backs to those who want to keep that from happening. A lot of what the Pattersons mean by their shrill cries that Mira wants to use their family politics to enslave them is that they fear that she will swoop down and inflict the horrors of common sense and real practicality on them and thus ruin their lives with her evil logic, order and dignity. Why, if she had her way, children would be paid attention to, Mike would have lived an organized life and had a productive career and, worst of all, he might have started thinking for himself and thereby not subsidized the retirement of two entitled old dimwits who didn't want to live within their means when they were working because that was unfair.