To be fair, he still wins it every year with a landslide margin, so one can't really say the organizers are plotting against him.
Take FIS for example. When they grew tired of Stenmark winning, they invented Super-G. When they grew tired of slalom specialists turning tables in combined, they switched the order of disciplines. When they grew tired of Kowalczyk winning Tour de Ski, they organized it with 5/7 stages in freestyle.
All things considered, Sagan should feel lucky that the organizers never went for such drastic measures in his case.