I do, and Snape wasn't it. He was a monster working for two even worse monsters: Voldemort and Dumbledore. Both were vile; Voldemort was just more open and honest about it. Dumbledore manipulated everyone to achieve his goals, refused to share any information until it was next to too late, never even trained Harry to fight and survive. When you look at the center of a web like he spun, you don't find well-intentioned old men, you find spiders.