That, friends, is John's image to most of the random passers-by and Milborough mutants: a juvenile clown who spends his time playing with toys. While some realize that his being an overgrown kid transfixed by self-absorption and cruelty might be why the woman yells, others might assume that she ate away at his dignity and caused him to revert. Either way, it's agreed that the shouting idiot who spends her time with the scrawny weirdo who kicked her gay son out of the house because she thought that people cared bellowing about how impractical his ambitions are and the grinning freak dressed like an idiot deserve one another.
(That being said, he has a second image to anyone young, female and presentable: the slobbering perv who mentally undresses you in front of the shrew wife who thinks you WANT to be ogled by some ape who can't control his throbbing urges.)
Either way, their being horrible people explains a horrible thing: why and how their children grew up to be horrible people in their own horrible right.