Walking Dead, Game of Thrones, numerous other shows.
"I'll stop watching (Show) if (Character) dies!"
Characters die in any long term mature series. It keeps things interesting. Why does it have to happen? Look at it this way. Hershel and Billy had to die. It was the best move. If they had stuck around, Maggie wouldn't go suicidal, then Maggie and Glenn wouldn't have as strong as a bond. Plus if Hershel AND Billy were around, it would mean Abe's group would get LESS screentime and less development. Also, what could they provide in a unique way? Deaths of characters push things in a new direction. Imagine if Lori stuck around. (On the road: Rick, I'm thirsty, you aren't raising Carl right, I need tampons, this is a bad decision like everything else you do!) Carl would not have changed into the man he is today. Some characters have to bite the bullet, and man sometimes it hurts. It hurts in a good way.
Try not to get too attached to what a character can do. Focus on how they interact with other characters and the story to see what makes them memorable. When Tyreese took a slicing to the head, I flipped my shit. I was so angry, I refused to read any more. But after a while, I realized why I truly liked Tyreese was because of the relationships he built and the tensions it created. Tyreese was a football player, but kind of boring until he started to interact with more people and things got serious. That fight between him and Rick was amazing, and it impacted Rick for probably the remainder of the series. When Glenn died, I was all like ;~; and Maggie was all like TTnTT and it was intense. Glenn meant so much not because he was a cool character, but because it wasn't the same without him. Get interested less in characters, more in what happens. If you are bored of characters and only like Daryl, just wait until he dies. Shit is going to hit the fan. Characters will change. Comic Andrea... things are going to get crazy when she dies.
I'm rambling too much. Focus on the drama and interaction, not if someone is going to live or not, you might just find yourself enjoying the series a bit more.
So what are your thoughts on deaths of characters and "I'm done if (character) dies" fans? Do you think some characters must not die?