I know you don’t like Snily (and it’s okay) but what do you think about the massive anti-snily culture on Tumblr? I ship it but I do know it’s problematic and extremely flawed. I tend to like fucked up ships. I’m not even trying to pretend it’s all healthy and lovey-dovey. I’m just so tired of being treated as a simple, silly fangirl. I love marauders, I have nothing against Jily but I can't help feeling that I'm not welcome to the fandom.
I don’t know what you mean by “anti-Snily culture on Tumblr.” I don’t follow people who ship and post Snape/Lily (as a conscious choice) so I’m not knowledgeable about that part of the fandom on Tumblr or how they’re treated.
If people are sending you hate for shipping Snape and Lily, or posting hate in the ship’s tag(s), or openly insulting the shippers and even reducing to slurs and name-calling, then you’ve every right to get angry. That sort of ship-shaming is gross, and sometimes even borders on outright bullying the shippers. Tell them to go fuck themselves, block and report them. No one has any right to hate on others for their fictional ships, even though they may find it disturbing. Sending hate and bullying is never okay, especially given how we’ve many ways to avoid the ships we hate, like blacklisting the said ship or unfollowing the shippers.
However, If what you mean by “anti-Snily culture on Tumblr” is people posting their (untagged) anti-Snape/Lily opinions on their own blog, or not following Snape/Lily shippers, or refusing to make and reblog Snape/Lily stuff and so on… then I’m sorry but I don’t think you’ve any right to complain about that. People are allowed to think a character or a ship is terrible, and openly refuse to contribute to that part of the fandom. We don’t have to gif, talk about, follow fans of every character and ship of our fandoms just so everyone feels welcome. That would be like me expecting Ron/Hermione shippers to make effort to make me “feel welcome” as a Harry/Hermione shipper, even though they may have issues with the ship. They have no obligation to cater to me. It’s just not going to happen.