Sad, but true. About the only way to control it would be to require online comments to be directly identifiable to the person. Even Republicans appear to be embarrassed - and attempt to expunge their vitriol - when their homophobic, misogynistic, and racist comments and activities online are publicized. And even that wouldn’t eliminate it, it would just push it back underground to further fester.
Its a joke - yes.
Though, realistically, an empathy test would probably filter out a large portion of the haters. It’s harder to hate when you internalize the condition of others.