This has been known for a while, the Melee fanbase has been called toxic since shortly after Brawls release. Even the well known Smash documentary touches on this: https://www.youtube.com/playlist?list=PLoUHkRwnRH-KTCH3tJ9WvsWWPEgUu-y6d check it out if you havn't. Its a great watch.
Part of why Smash fans get so crazy and sometimes downright nasty over Melee is just due to how they've been treated for a long time. A lot of people thought and still think that Smash is not a competitive game, that its easy or is too simple or has no depth. Melee players and fans have been through a lot to grow their game and the smash scene. Hell, even the creators of the game have been against them at times. Imagine helping to grow and nurture something you love only to be told over and over again that your stupid for doing it or loving it. Then imagine that even the people who made the thing you love come out with another thing that literally takes away everything you loved before.
Don't get me wrong, that sort of behavior is bullshit and needs to stop, but I do get both sides of the story here. Hell look at CT ISAI, he loves SSB64 more than SSBM and went back to it after a while. Everyone has their own favorite Smash game for different reasons and thats what makes the game and the Smash scene so great imo. People would do good to remember that.
“What I say is, a town isn't a town without a bookstore. It may call itself a town, but unless it's got a bookstore it knows it's not fooling a soul.” - Neil Gaiman
