*bows down* Thank you for taking the time to explain it so fully, JF.

I think there are a lot of people in the HP fandom who feel just as strongly about this ship as you do and even go so far as to disregard the last book entirely.
Actually, I was listening to SnapeCast the other day and they had a roundtable discussion on something they called the "Snape divide" which occurred in the fandom after the release of Deathly Hallows. Snape, it seems, has always had his fans split in half. After HBP we all chose sides as to whether he was good or evil, and now it seems we're all choosing sides as to whether we like post-DH Snape or pre-DH Snape.
Obviously I couldn't help falling more helplessly in love with Snape's character after the events of DH, and in my humble opinion I believe his love [you could even call it an infatuation] with Lily helps break Snape out of the "villian" mold he was cast into to begin with.
However, there are people who believe that Snape being in love with Lily makes his character weak and two-dimensional. Some may even argue that JK Rowling has also made him into a rather creepy character for continuing to love Lily long after their friendship was over. These very same people also believe that JKR made Snape this way to punish the character who is based on a teacher whom she did not like in her own life.
I definitely suggest listening to this discussion as it really was interesting. At one point I got a bit confused and couldn't decide which side I was on! Here's a link -
SnapeCast