I finally watched this. All the brothers had artistic talent; all could have made some kind of a living as artists of some kind, but only Robert succeeded. This isn’t a story of garden-variety dysfunction and disappointment; Charles and Maxon were both pretty seriously mentally ill, and completely non-functioning adults.
The comparison to George Sodini is poor; he functioned pretty normally in society and had a mentally demanding job, but ended in murder-suicide due to his personal frustrations. Charles and Maxon were chronically mentally ill and unemployed and don’t seem to have had much everyday cognitive functioning. Robert’s success in life can’t be attributed to fame and fortune; before he became famous he was married, had a kid and worked at a greeting card company, the kind of ordinary work most artists do.
The Crumb family simply seems to have been a fertile breeding ground for mental illness; his mother’s amphetamine addiction being both a cause and symptom. What was going on with his father I can’t say, but if he was involved in combat in the war that is probably a big part of it. There was a lot of combat-induced mental illness among World War II veterans, but it was mostly ignored.
Not everything can be looked at through the prism of social behavior provided by game; some things can’t be fixed, and they can barely even be lived with. R. Crumb dodged a bullet in his family, his brothers weren’t so lucky.