You've made several erroneous assumptions about my opinions, not based on anything that I have said. I did not like Hallows. I thought it was a hodge podge with many loose ends and illogical plot diversions. I didn't think that she needed to introduce the Deathly Hallows as a concept. They were an unnecessary distraction. Sure there were loose ends, but all stories have those. On the other hand, I never thought that Snape was a great figure in literature in the previous books. He was always the "stand-in" villain, since the real baddy couldn't be on-page the entire story, and the stories needed some internal conflict to keep them interesting.

I didn't like what she did with Snape in Hallows either, but that was because I thought she made him too romantic, and that didn't mesh with her previous treatment of him. I had always thought he was on the good side, but that he was a nasty jerk. I even thought he loved Lily because that explained the remorse that Dumbledore mentioned.

I thought that Snape plenty of forgiveness by Harry when he named his son Albus Severus. Therefore we didn't need more vindication for Snape than that.

My issue is you or anyone else is blaming Rowling for not writing the book you wanted by claiming she changed her path, and I've also seen that said by various proponents of ships. Even though I didn't like Hallows all that much, I will never be so arrogant as to claim she made a mistake not writing the book I wanted. She wrote the book she wanted. I could see it was always the book she wanted. Snape was never intended to be a great literary figure. He was never someone to like. It's very hard to understand anyone finding such a nasty person appealing. He was an interesting and complex character, but never one to admire.