People just like Melee. If people wanna play Melee, seriously, where is the harm in that? If they don't want to move on because they don't like the newer games as much or at all...that's okay? I mean, really, it is. It's harmless personal preference in what someone thinks is fun.
I like Super Mario Odyssey and think it's the best 3D Mario ATM. However, that doesn't mean I feel any Mario before it is all of the sudden invalidated or people who don't agree with me are "elitists" or "stuck in the past".
Basically, if you don't like Melee and don't wanna play it, cool. If other people do, also cool. Play what game you wanna play, as there is no objectively "best Smash" when that notion itself is completely subjective to one's tastes, and disagreeing with someone on the taste in a video game doesn't make someone "toxic" or "elitist".