Interesting points about first person in fanfic. I'm not all that particular when it comes to reading certain POVs. Writing, yes - I prefer third person - but reading, it's all good as long as the POV works. But thinking about it now I've come to realize that there are not many fanfics written in first person POV, and the few that I've read - very few - did work, but only because I read them in the early days of the fandom when the characters weren't as established for me as they are. Now that the characters are established, I'm a lot more picky.

So, really, for me, it's not so much an issue of POV but characterization. First, second or third person, if how the author sees the character doesn't fit with how I see the character, then I hit that back button pretty quick. I know it sounds a bit arrogant but there are some characterization tropes I can no longer stand. Kirk!Sheppard, for example. Or idiot!Sheppard.

But some excellent points were made about first person, because it is dangerous waters to sail when it comes to fanfic canon characters. You not only have canon characterization to contend with, but personal preferences as well - your own and your readers' preferences. And I think first person POV has a way of making it feel like the author is setting the character's personality in stone, and if it's a personality someone else doesn't agree with, then it's going to tick them off enough to quit reading. At least that's my own personal impression of first person.

Everything said could also explain why I can never bring myself to write first person in fanfic. I've thought about it, but can never bring myself to do it.