John Oliver: why do we only talk about mental health after mass-shootings?

https://www.youtube.com/watch?v=NGY6DqB1HX8

John Oliver's segment on mass-shootings and mental health makes all the right points: making the issue about mental health instead of guns stigmatizes mentally ill people (who are more likely to be shot than shoot someone), but since we're on the subject, the American mental health system is a disgrace.