Not them but I was never fond of Meowth for mostly these reasons:
-He hasn't been relevant as a Pokemon for a long, long while.
Correct, he is currently not relevant in the Pokemon games other than Pokemon Shuffle... on the other hand, he's one of the few iconic Pokemon outside of the games not playable in Smash... and Smash is marketed as a Nintendo All-Star crossover fighting game.
It makes more sense to add a famous and recognizable Pokemon like Meowth over an obscure Pokemon like... what's its face even if they are more popular than Meowth. For example, Takamaru was the more popular retro choice yet Duck Hunt Dog (a retro choice most people here scoffed at and dismissed) got in over him because he's more famous and recognizable.
-Just because Sakurai toys with the idea, doesn't mean he wants him in as of now.
Like how he didn't change his mind on
? Do I need to be like the Ridley fans and hope that Sakurai won't work on SSB5?
-Generation 1 has 4 Pokemon in the game and 2 that were cut, Pokemon can get more reps but we don't need any more G1 Pokes.
Yes, we don't need any more G1 Pokes but we will still get hyped over getting even one more G1 Poke newcomer anyway... and that's more important than meeting arbitrary quotas and slot numbers.
Hell, I know people will get hyped for
if they were confirmed to be coming back despite the popular claims that we don't need any more G1 Pokes.
Yeah, people say they don't want Meowth but I suspect they will be hyped if he is unexpectedly confirmed. People have a tendency of wanting something they didn't know they wanted when they see it with their eyes.
-Meowth isn't popular at the moment and the
argument is moot since she got grandfathered in. There are insanely more popular Pokemon and Meowth hasn't been one since the anime and the anime has been ignoring Team Rocket since BW's Plasma vs Rocket arc.
And yet people will still get hyped for Meowth and/or Team Rocket if they are unexpectedly confirmed whether they wanted them in or not... and if there's a legitimate leak that claims Meowth and/or Team Rocket are in Smash, people will just jump on the bandwagon and claim they wanted them in all along. *cough*hipsters*cough* That's how Duck Hunt Dog and Chorus Kids suddenly became insanely popular last year.
When you say there are insanely more popular Pokemon, are you talking in the context of the Pokemon fanbase or the Smash fanbase? The Pokemon fanbase tend to flock toward competitively better Pokemon... whereas the Smash fanbase generally only wants the veteran Pokemon and maybe at least one newcomer of their choice. The newcomer is usually the most recent Pokemon the Smash fanbase will instantly support because they think it's a shoo-in like Zoroark was (and yet they couldn't agree on the 6th gen rep before Greninja was confirmed). I am waiting for the 7th gen Pokemon bandwagon to commence. Who knows? Maybe it will start at E3 2015.
Moveset was never the issue.
Good. Then hopefully more people will refrain from using the tired "not unique enough!" and "no moveset potential!" arguments against Meowth.