Contrary to common belief, many Marauder fans don't hate Snape for being a Death Eater (those who they claim to be literal Nazis, racists, or whatever other type of bigot), or even for his actions. They simply hate him because their self-inserts hate him and the voices told them to (plus, Snape is simply not attractive or rich enough for them to imagine getting railed by him or other men railing him).
How do I know? Because of their very loud worship of other Death Eaters like Snape, or who, in some cases, are way worse than him. Said Death Eaters include:
Barty Crouch Jr. (a grown man who impersonated a teacher to get closer to a traumatized 14-year-old child so he could set him up to be murdered by the man who murdered that child's parents and left him parentless, and when it didn't work, he tried murdering the child himself. Who was looking through the robes of said child with a magical eye. He was basically taunting yet another 14-year-old traumatized child with the Unforgivable Curse he himself used on said child's parents to drive them to insanity, leaving that child parentless. He then turned a child again with the 14-year-old… into an animal to fling him around and repeatedly bash him into the stone floor, and no, idc how annoying or bad that child was, there was no justification for this adult man to slam him repeatedly like that. He handled that situation terribly on purpose because do you think he cares for any of the children that get hurt or who he hurts? No, because he is literally actively planning the murder of one, which is the child he was "protecting" in that scene, mind you. AND ALSO, when he catches Lavender reading a magazine under the desk with his magical eye, he calls her out, yet his magical eye, which can see through pretty much anything, was still fixated on her even after). Oh, but they love to imagine him as some sort of secret activist punk who was fighting the good fight, or really wanted to but couldn't, and who would actually love the weirdos and the outcasts, the gays and the oppressed, or any minority groups out there. He just has some issues, all being his father of course, who was just an oh-so-terrible man for wanting his sweet, innocent, wittle baby boy in prison. I mean, how dare he?! /s
Evan Rosier (an absolute nobody who was killed by Moody while trying to resist arrest for his criminal activities instead of going calmly). Someone they imagine as black (or a poc) for some reason? Idk, I guess a bigoted, black, “racist,” “Nazi” is better and more justified than a white one (but don't even think about imagining Snape as anything other than white because it's just wrong). Who knew? And the imagery of this now black man trying to resist arrest, only to die in the altercation, is just the icing on the cake. Really great! /s
Regulus Black (another nobody who was obsessed with Voldemort, downright a fanboy, but then became upset at Voldemort for hurting his house-elf even though he volunteered Kreacher to him, and decided to try and take him down or weaken him, only to make future Horcrux hunting harder for Harry and the rest). Everything about him is literally just reheating other characters nachos. He gets their characterizations, their accomplishments, their narrative importance. He's basically just a Frankenstein character, where he has a mixture of others put on him to build him up into what he is. Harry was the youngest and best Seeker? No, that was Regulus. Harry was the Chosen One and defeater of Voldemort? Nope, it's actually Regulus. Lily is important to the narrative and haunts it? No, no, it's again Regulus. Snape was masterful at potions and knew more curses when he arrived at school than half the kids in seventh year? Clearly, you didn't read the books because that's actually our good sir Regulus Black!! Which, it's ironic that they bash Snape for that last bit of him knowing more dark curses than everyone else, but give it to Regulus and praise him for it because it shows just how smart and powerful he is.
(FYI, I'm in no way hating on anyone who likes or stans these characters, nor am I saying that you can’t. Heck, I even enjoy them and their craziness, but this whole thing of bashing Snape for things you praise other characters like him for is insane and so hypocritical. Especially when it’s all fanon nonsense. You can’t hate a character for how they canonically are in favor of characters you simply project onto and won’t actually recognize as they truly are. Also!! nowhere in here am I defending Snape. He was an awful person who made terrible decisions, so don’t try to make this into something it’s not by accusing me of being a “crazy Snape apologist” or whatever. All Death Eaters are bad and gross at the end of the day, cheers)