If the point isn't about separating good fanfic from bad one, what your goal?
My goal is to stop feeling revulsion when I read something I'm ideologically opposed to.
Perhaps a good question you should ask yourself is what do you want to feel, and under what circumstances?
For instance, take racist literature, young earth creationist literature, and political opposition literature. It is entirely plausible that you would not have the same new reaction to reading those three things, even though you are probably ideologically opposed to all three.
By breaking it down, you can take an approach that notices that when you read literature A, you react differently when you read literature B. Maybe literature B is less revulsive ...
I was reading a review of Trust in God, or, The Riddle of Kyon. The reviewer went through step by step and listed problems with the fic. Some of them I agreed with, and others did not. What really stood out was in a comment agreeing with it: "reading that fic usually just evoked vague anger and other unpleasantness." Not unlike the vague feeling of anger and other unpleasantness I felt upon reading the review.
I don't consider myself someone whose opinion can be trusted on the quality of the original fic. In addition to being every bit as biased as any hater, although in the opposite direction, I have Asperger's syndrome, and I don't trust myself to notice such things as people acting out of character. However, because of this, I know my revulsion cannot be due to the quality of the review. I looked for it in hopes of weakening any bias I have. I think I can safely say that my revulsion will prevent that from happening.
So, any idea on what I can do? I've always thought haters should just stay away from what they hate. That would work fine if I just hated ponies or something, but I don't think it's such a good idea in cases where ideology is involved. And if nothing else, I don't want a vague feeling of anger and unpleasantness to ruin a perfectly good fanfic, like The Death of Haruhi Suzumia.