I don't understand why some media ends tragically, with the bad guys winning or with everyone dying. Don't humans watch/listen to media for entertainment? What's entertaining about a grim and depressing conclusion to a team's adventures? Or a tale that ends on a sour note because the media wants to impart some kind of life lesson about things? I don't give a Kentucky Fried Fuck about life lessons. Tragedy is not instantly equatable with telling a worthwhile story.
I don't mind sad things happening at all. I've seen a lot of media where sad things happened, but ultimately everything turned out okay. But sad things happening isn't the same as forcing your audience to wallow in agony for no fucking reason other than to manipulate hormones to produce an effect of despair.
I don't need you to explain the concept of the "tragedy" genre to me or to argue my preferences; I am not stupid. I just think that nihilistic endings and unnecessary character deaths are bullshit, and don't add the gravitas some media creators think that they do.