Wow, those tweets and replies are filled with either a complete lack of reasoning or garbage reasoning.
First of off, I don't have a horse in this race, so to speak, because I don't play Miis of any type in vanilla Smash 4. However, my views tend to skew a bit more liberally when it comes to the Smash ruleset in general (i.e., I want to see customs legal again). So inevitably my bias is going to be towards Mii legality. With that said...
I want to play Smash and not Mario Party
What kind of logic is this? Mario Party is utter rubbish as a competitive game because, by its very nature, RNG plays a huge factor in determining the events and flow of the game, and losing players are usually (though not always because RNG) awarded a bonus near the end of the game, among other things. Mii customs are neither random in effect - helicopter kick will always do helicopter kick things - nor randomly acquired, as all new save files start off with them already available. Your Mii will also have the same moves every time you use it, especially if the rules forbid creating new Miis mid-set (which MLG did). There is nothing random about it, you can prepare for the individual moves, it literally requires spending just a few extra minutes of your time to learn what moves do what. In most cases, Mii players, or at least Mii Brawler players, tend to use the same optimal set anyways. So random luck is not a factor, and the better player will win,
period. Unless you're grossly under-prepared to deal with Miis, I guess, but that's a failing of the player and not the game or its ruleset.
I don't think it'll last, homie. Tough it out like we did customs the first time... Just have to believe in the greater good.
This implies Mii customs are equivalent to other customs...when they really aren't. The games treat Mii customs separately from all other custom moves, from how they're able to be used when customs are turned off, to the division between Miis and other custom fighters in the customs menu, to how they're used in online tournaments. Besides that, Mii customs were also very intentionally balanced and their effects feature a drastic amount of differences from one another. The only other character in a similar spot is Palutena, who receives similar (but not equivalent) treatment to the Miis by the game.
Most customs are just variations on the standard attacks, and are arguably not competitively viable. I tend to disagree with the reasoning most anti-customs use (simplify neutral game, it becomes over-centralized over certain characters and moves) because the players who performed well in those conditions also performed well with the same characters in vanilla, and standard Sheik dominated anyways but I digress...it's pretty clear the moves weren't intentionally balanced up until the most recent balance patch, bug fixes aside. Mii custom moves
have been however, because every single move a Mii can use is effectively a custom move. The game might set the 1111 as a default when you first go into the menu, but that because something needed to be default if you just want to power through the menu - that doesn't make them the standard move the characters should be judged on.
I'm just kinda...baffled, really. If you want Miis banned, you have to provide sound, logical reasoning. You can't just whine that they're random (they're not) or unbalanced (also not) without providing clear evidence that custom Miis are broken or make the game worse by existing (I...don't see how that's the case?).