Why ladies amor Severus Snape 

Yeah, I have to agree with them, completely. Great link.

I too agree totally with the writer. Though I'd like to add a 6th point :

The need to right a wrong and being unable to do so.

It sits very uncomfortably with me that he had such a sh#$ty life, was misjudged by everyone and then died alone and hated. He didn't deserve that. I guess because the books are written from Harry's point of view, I can't help but feel bad for Snape and somehow take on some of Harry's feelings of gilt about the way Snape was treated. If I see injustice, I want to act on it and fix it and make things fair again. With Snape I feel that life robbed him of justice (he didn't even get to see the fruits of all his years of sacrifice). Snape's life and the circumstances of his death elicit feelings of sympathy, regret and a yarning to do lots of good things for him so as to bring balance to his life.

Absolutely dead on.