In all fairness, he didn't say seniors were prepared to die, he said HE was prepared to die.
He is known for being quite a renegade and doesn't represent the way most of us feel, regardless of political affiliation.
His argument was that more people will die from a world-wide depression than from the virus. He obviously overlooked that such a depression is far from a reality, more a very remote possibility.
Much is being done by people around the world to develop treatment and prevention drugs and the restrictions in place will slow the spread of the virus until these projects are realized.