Hey guys, rebumping, and I'm a melee player but consider myself a reasonably objective one at that. HEre are some of my speculations.
Though Sm4sh has the lead in numbers as of this last year from my understanding, Melee has the lead in viewership numbers. There are reddit threads that try to dissect the data and everything. However the previous comments that were made regarding Melee not being as accessible as Smash 4 WiiU are arguably being nullified more and more day by day, because now there are cheaper accessible alternatives to playing melee in the form of emulators and netplay, or faster melee. To the extent that Melee has become as close to accessible as other cross platform and PC games. That doesn't even take into consideration that by playing melee on a pc you are not restricted to using a gamecube controller and adaptor but can even use a keyboard or xbox controller, or arcade stick. This isn't including the 20xx training hack packs and other mods like TE which are more resources for players who can learn more from their replays and pre program inputed training bots. Which I believe in theory has something to do with why Melee is a few hundred players behind in entrants to big tournaments, but often times significantly leading in tournament viewership. Another weakness I see from the melee TO's that may hurt the melee tournament entrant numbers is the reluctance to allow Smashbox/ arcade styled controllers into the tournament legal ruleset, which would be a strong growing point if Melee viewers cross over with other FGC viewer bases. Another point that has been brought up to some extent is the development of each game's meta and how despite Melee's ever impressive depth the meta is supposedly set in stone and stale, whereas smash 4's is still fresh and new. (with the exception of complaints about how broken bayonetta or cloud are) Arguments that have some truth to them, but also aren't the 'be all: end all,' in my opinion. Melee has had some mid/low tier character upsets spring up as of the last couple years, and though the streamlined "optimal" play at the top does get tiring to watch it just goes to show there is more to be discovered in the under developed characters that can still change the meta. That is why low tier character knowledge in melee and character knowledge in general given smash 4's case is something that should be shared more thoroughly. However I believe this issue may to an extent be partilly due to the difficulty and patience it takes to play, learn, and implement successful gameplay with under developed characters, and people wouldn't want to share certain bread and butters or options for the sake of claiming the fame themselves. Soooo, it's all an interesting tossup. Melee likely has more players, that would prefer just to be hidden bosses through netplay ladders than compete in person, it's cheaper and similarly enjoyable if you just enjoy playing the game for the characters and engine(especially if they play with a controller that isn't a GCC).
Lastly, this may be getting long, but another theory I have is parallels between fighting game character archetypes: Grapplers, Zoners, Vortex Characters, Tech Trappers, Shotos, well rounded characters, Heavy Hitters, Light Chippers, and any combination and speed/weight classes of the above. This is where my lack of experience with Smash 4 will show as I can not classify any of the characters in that roster among these styles most relative to the street fighter series (which is the holy grail of fighting games) but Melee appears to incorporate these traits in their characters in such a way that their archetypes or at least styles are significantly noticeable at a glance. This is further emphasized by the significant differences in weight/gravity speeds of characters and why different characters pressure shields or take certain stage positions relative to their toolkit's strengths. One can even go as far as saying the parallels are even obvious for example:
Fox Upsmash ~ Remy's Rising Rage Flash/Guiles Flash Kick
Link/Donkey Kong's Grounded UpB ~ Zangief's Lariat/Ryus Tatsumaki Senpukyaku
Falco's Lasers/Samus Missles ~ Remy's Light of Virtues(varying height/speed projectile)
Link/Young Link Boomerangs ~ Projectiles with varying angles for reading jumps (ie Urien/Akuma)
Shek/Peach's DownSmash ~ Akuma's Tatsumaki Senpukyaku
Sheik's Needles ~ Ibuki's Kunais
This is just a short list off the top of my head, and I'm sure there are more, also any juggles and chaingrabs/tech chases grant multiple characters grappler status for the fast faller match ups. However, I don't know whether mechanically in smash 4 these character traits bear resemblance in play style and archetype to said games. Because i'm sure pacing plays an important role too, and to an extent maybe they are more similar, but graphically smash 4 would lend itself to seem more like SFV. But this is speculation as I do not have much experience playing smash 4 outside of at a bar in downtown riverside on wednesdays when they have game nights. OH! Also community TO's and communities also contribute to the longevity of the game, I have been running Monthly Melee Singles tournaments in San Bernardino at the Brew Rebellion Brewery for almost 2 years now and have recently started doing biweeklies, because it ensures that I have people to play against and get enjoyment out of creating a home for the local smash communities in the Inland Empire of Southern California, and additionally, San Bernardino was one of the city's that filed for bankruptcy because it really has no culture and news outlets like the LA Times are consistently bad mouthing this city in order to make LA look better. So I'm very aware of how social politics affects local economies. Me doing tournaments has been a boon for not only the melee players here, but also a source of revenue for the brewery to stay open here, it's the first one we've ever had. So What i'm saying is, multi faceted problems, have multi faceted solutions. Also I don't run Smash 4 tournaments, because someone else already runs biweeklies for them, and we mutually reached out to each other to experiment with hosting biweeklies on the same days. Presumably in case there is any cross fertilization of entrants.which coincidentally has only happened from smash 4 players who like melee entering my tournaments, 1 each week. If you were to ask me my opinion on why I or most other melee players won't give smash 4 an honest effort, it's because the game doesn't quite feel as rewarding at first, the changes mechanically are really odd, because to me it feels like there are less movement options in a game that I believe relies more on movement than anything else. Movement is an important part of what makes characters viable, in my opinion. Anyway, I hope this strikes up some constructive, creative conversations for how we can work to build sustainable competitive gaming scenes for the benefit of our players, as well as for our regions, some of which are in dire need of economic engines like Esports to bring something new to the area.