I have a conspiracy theory for that. I read Ferrari had complained to FIA (stands for Ferrari International Assistance, not Fédération Internationale de l'Automobile) that there was something illegal in Red Bull's car. Maybe FIA had promised not to give a penalty to RB if they sabotage their own cars, costing them the championship. I read a conspiracy theory in '07 that McLaren had to lose the championship because of the espionage controversy, and that's why they didn't pit Hamilton in China before his tyres were worn out. Maybe this is something similar.
Anyway, I'm so pissed of that penalty that I'm more that willing to skip watching the Abu Crappy GP to see the Paris TMS final with a new TMS winner.