I hereby decree…
Snape was an asshole.
Alright, if a warning is still needed five years later, the following contains Harry Potter spoilers.
Okay then…
Severus Snape was an asshole and deserved what was obviously an awful death by Nagini the snake.
Oh, what’s that? He was a selfless hero?
Maybe. He might have actively tried to save Harry’s life a couple of times and was integral in Voldemort’s downfall. But it doesn’t change the fact that he was an asshole.
It doesn’t change the fact that, having saved him or not, he still treated Harry like shit for several years. Ron and Hermione, too.
Okay, Snape was butthurt that James Potter bullied him at school and married the girl he was in love with. I can see how that sucks. But treating their son like crap about it, their son who never did a thing to him except be James Potter’s son, is inexcusable.
And yet, at the end, we find Harry has given his second son the middle name “Severus” and was telling him that the man his middle name comes from was the bravest man he had ever known. Snape hands Harry a memory strand as his last action, and suddenly Harry forgets everything else and decides Snape should be ordained as a saint or something.
It’s an interesting philosophical thought, though. Recognizing someone for having done something heroic despite that person having in general been a total vindictive asshole. One might call it forgiveness. But this goes beyond forgiveness. This is reverence. Reverence by the main person to whom this otherwise hero was decidedly awful. And it wasn’t even for-his-own-good awfulness. None of the other Hogwarts professors were anywhere near as disrespectful and downright cruel to Harry as Snape was (well, except for Umbridge, of course!). And that’s even considering the two who turned out to be active Death Eaters. There was no reason for it. I mean, sure, he was helpful and heroic and brave and all that when it came to taking down Voldemort. But why be a jerk to Harry? Because he was sad and heartbroken about Lily?
And even then, that didn’t explain why he was nasty to Ron, Hermione, and Neville. And to anyone who wasn’t in Slytherin for that matter.
Come on, Harry, should have named him Albus Remus instead.

I’m still not convinced Snape wasn’t playing both sides till the end.
And “Albus Remus”? No. Remus maybe, but not Albus. Harry’s biggest mistake is remaining loyal to Dumbledore.