Hang on. Blowing up miserable planets doesn't increase total happiness, it increases average happiness. Tell the tobot that its error is making you less happy, so it should blow itself up.
Aliens invade: "EARTHLINGS, WE HAVE KILLED YOUR LEADERS, DESTROYED YOUR ECONOMY, AND ARE HERE TO TAKE OVER YOUR GOVERNMENT"
Hang on. Blowing up miserable planets doesn't increase total happiness, it increases average happiness. Tell the tobot that its error is making you less happy, so it should blow itself up.