>Let's determine who dies by what the TeeVee says
Fucking lmao. Also, Light was an impulsive retard. If he hadn't killed L's body double, there was no way he would ever have been caught and even later he acted stupidly with how he killed the FBI agents(When anyone would have reasonably concluded doing so would immediately draw further attention to the people they were investigating prior to their murder).
Tbh of the geniuses in the show, only L acts like one. We are constantly told Light is brilliant but he rarely does anything smart(Although that might be just the character bowing to plot requirements). All he'd have to do is send one message threatening he'd kill major world leaders if the investigation didn't stop and it would stop. He never does that.