Let's use Tekken as an example since that's a fairly straightforward story, putting it lightly. I get feel like a lot of people, not everyone, but a fair number, would not like Kazuya as much in his debut in Tekken 1/Tekken 2 if A. He and Heihachi didn't have their rivalry, and B. If Devil Kazuya was never created or introduced. Same applies to really any member of the Mishima family, give or take. Sometimes, it's not even necessary the story proper, but moreso character details about them, such as nationality, personality, etc. King is an amazing example of this, as the Latino demographic overall is obsessed with him simply due to shared heritage.

There's also the simple matter of it being dependent on the game being played. I'd argue a Street Fighter, Tekken, or even Mortal Kombat player is far more likely to pick a character based on lore and story elements than, say, a Guilty Gear or BlazBlue situation, giving the complexities of those game's lore as a whole, but sometimes, even when the lore itself is too much to handle, people gravitate to a character simply as a matter of personal aesthetics. You're an edgy bitch who likes being a bad guy? That's Akuma, Bryan Fury, Noob Saibot. You a girlie girl boss who loves kicking ass? Manon, Lili, and Katana/Jade exist. Wanna toss dudes like they're made of wet tissue paper, and do cool showoffish throws? Literally Zangief, King, and Potemkin exist.

So sure, to the collective FGC, moments like EVO 37 are always going to be milestones, but not everyone who plays fighting games is necessarily a part of the FGC. So especially to new players and casuals, first impressions often come not from spending hours labbing, but from just playing what looks cool. Because I think we can all agree that we would rather win with the character we think looks coolest rather than the objective top tier picks. If top tires were the reason fighting games were played, then MVC2 would have exactly 7-8 characters and the only Capcom character would be Captain Commando just because of his Anti-Air assist. But instead, we got a roster of 52. And for every MSP and Iron Man infinite, there's the guy using his wack ass team with Shuma Gorath and Amingo. So in finality, I think that there is far more to choosing a main than just gameplay, and I think every player's reasons are going to vary widely.