Guns and mental illness

Politico runs an article with this headline and subheading:

Allowing the Mentally Ill Guns Is Insane

The Oregon shooting is a tragic reminder that the laws on the books are woefully inadequate.

The article says:

The National Alliance on Mental Illness and the Substance Abuse and Mental Health Administration caution against creating special laws aimed at the mentally ill, including laws related to gun violence. SAMHSA indicated that subjecting the mentally ill to extra scrutiny perpetuates the misconception that the mentally ill are especially violent. This stigma, mental health professionals warn, increases the tendency of the mentally ill to avoid treatment and counseling. Though this is a valid concern, the safety of the public must be weighed against it.

But if that's a "valid concern" weighing against barring the mentally ill from owning guns, how are current laws "insane," as the headline says? If there were a law saying no one who's been diagnosed with a mental illness (or any mental illness out of a certain list) can own a gun, wouldn't this predictably cause many people who want to own guns to avoid getting any mental-health treatment? And if mental illness is so strongly linked to mass shootings, then couldn't discouraging gun enthusiasts from getting treatment lead to an increase in mass shootings?