I also lacked any strong emotional reaction to Hermione's death and I have never read a superhero comic in my life. I fact, I've never had such a reaction to a fictional character's death in books, movies or games. While I do get immense enjoyment out of absorbing works of fiction, I never get 'caught up' in them to such a degree that the emotional part of my brain starts treating characters as real people.

I've never been into superhero comics so that can't be the explanation in my case. In fact I often get annoyed when an official writer mistreats the canon they have been entrusted with, or fails to follow up on important plot points.

I can get emotionally invested, but to me (it appears, upon internal reflection) it is the loss of potential and further interaction with the character that gets to me.

For instance, I really like the scenes including X, and I thought that X could have grown and done so much more, and now none of it will happen. Completely different feeling from when RL people die.