Someone argued that Lost preceded GoT regarding deaths of its main characters, but yes. I have no idea why someone could be convinced that we watch movies/tv shows or read books only to know if someone will die. And there are genres (like light comedies) which don't involve matters of life or death. Actually, I find the concept a little morbid.Oh, I would've liked that! I might have actually watched the series for once!
But, seriously, I agree with your main point. When watching a series (outside Game of Thrones), it's a safe bet the main characters will survive and that doesn't hamper your enjoyment of the show.