It's the same reason MMA fans get bent out of shape when they feel their favorite fighter isn't being treated fairly, or conversely when a fighter they don't like is getting special treatment. When you see someone who is an extremely talented, hard worker it's normal to think it's unfair if that persons work isn't recognized just because the boss likes someone else better. We watch sports to escape mundane day to day activity. When we see the people who we watch to escape going through the same BS we do at our 9-5 job it's pretty normal to get a little salty about it.
See this is weird to me.
First of all, its not a sport where what happens actually matters.
Its more like acting, its acting with a lot of stunt stuff, really, and winning or having a title or anything really means nothing, not a damn thing. It was just written that way by writers or it wasn't, like a script in a show. The only thing that matters, is the fan's reaction to what happens.
As to acting. If Jon Snow dies again next season and
@conor mcgregor nut hugger complains about [actor's name] getting treated unfairly by their bosses because of it, then everybody would think: what a freaking weirdo to cry about that.