"It seems elitist and wrong"

I've made a worrying observation about my reading habits. I haven't been reading much fanfics lately, partly due to RL, and partly due to the fact that I have less and less tolerance for things that don't fit into my personal view on canon. Wading through the fics that I have saved for later perusal in the course of the last few weeks, I came across one which I liked a lot. It's got some of my favourite characters, it's got excellent characterisation, it's touching and well-written and lovely. But. It also works on an absolutely uncanonical premise, which I can't overlook, as much as I'd like to. This is something that happens a lot to me and stops me from sending feedback for an otherwide excellent story. As I don't want to point out that fic, I'll use a purely hypothetical example: Imagine this fantastic story, full of dark realism and understated communication, which works around the plot point that Peter is unable to cast the Killing Curse. In fact, the story is called "The Death Eater who couldn't kill". - No matter how brilliant the fic otherwise is, this uncanonical plot point would grate on my nerves so much that I would not be able to fully enjoy it. Am I too fastidious? I fear I am.

( And because there is no fandom-related post without a mention of Remus: )