>The worst thing my TV can do if hacked is stop working completely and forever.
Or turn into part of a botnet attacking other peoples websites. Maybe you're on a metered connection and you'll go over your bandwidth quota.
Oh, and maybe you have one of those smart TVs that responds to voice commands and can be turned into a listening device.
Maybe the firmware settings like to reset themselves on the TV every 6 months so it starts looking for the nearest open wireless to connect to.