That's certainly the case for many young people, who may have parents who didn't seek the answers they should have from doctors. It's probably also the case that many parents were going undiagnosed, with unchecked anxiety or OCD or maybe autism. In women it is very difficult to catch. Quirky, self-indulgent fathers who didn't seem to have the patience for their young children's normal antics could certainly have been dealing with something serious but hiding it from everyone. Thus, they come across as unloving douchbags who get ghosted by their adult kids. And then some people are just plain callous idiots. It is certainly complicated sometimes.