I was intending to make this it's own topic... but I might as well just put it here.
We've all read Sirlin's articles and like to throw quotes at each other. His well written case study on Old Sagat is of particular importance. The argument is that it might be beneficial to ban Old Sagat, because the metagame without him will allow significantly more variety.
The problem is not that Old Sagat is too good, because he isn't particularly better than the other "top" characters in the game. The problem is that he destroys the low tiers.
Think back to Melee. If you had to ban a single character from Melee what would it be? Fox is the "best", but most knowledgeable smashers, if they put personal opinions aside, would ban Shiek. Why? Because Fox may be good, but Shiek *destroys* lower tier characters into oblivion. Banning Shiek would make the lower half of the roster more viable. Fox may be better overall, but most characters would rather fight Fox than Marth, Shiek, or Falco! In fact, banning Fox would make Melee's balance worse by increasing the position of the other top tiers! With no Fox, Marth, Shiek, and Peach in particular would see even more play, making it even harder to play most low tier characters.
Now consider Meta Knight. Can you think of a single character whose worst matchup in Meta Knight? DDD and ROB probably, and maybe Mario and Pit, possible Link? Most the character I can think of have DDD, G&W, or Falco as their worst matchup. We all agree that the issue with Meta Knight isn't that he has too big of an advantage against SOME characters, but that he has a small advantage against ALL characters. So what would taking Meta Knight out do?
- DDD and Snake would instantly take Meta Knight's place above everyone else.
- DDD would probably be considered top until his counters proliferated the meta-game.
- Maining Mario, Luigi, DK, Bowser, and Samus would become futile in a world with an increased number of DDDs, much worse than it is now. The lasting damage to their meta-game would leave these character undeveloped.
- More Snakes would make characters with poor approach options even worse than they are now, but it's not as big of a deal as the DDD problem.
- G&W would stay about the same due to more Toon Link players.
- Falco and ROB would increase in popularity and become a popular secondary to fight Snake and DDD. ROB would probably be considered better than Falco.
- Wario would also see less play thanks to more DDD, while Marth and Ice Climbers would see more play thanks to no MK. Lucario would stay about the same.
- Community hatred of the Ice Climbers would rise as they become more common.
- As mentioned previously, more DDDs would reduce DK to "secondary against Snake" status.
- There might be more Diddy Kong play seen, not sure on this one. The changes to other characters have pros and cons for him.
- Pikachu will probably become slightly less viable, though no big change.
- Kirby should become less, due to increased play of his counters.
- Pit will almost certainly become more viable, being much better against the other top tiers than MK.
- Wolf probably won't end up too much better or worse off.
- Toon Link will increase in popularity a good deal.
- I honestly have no idea how Fox or Zamus would be affected. Everything points to something different.
- Olimar will probably become a bit more viable, but not as much as people think.
- Shiek and Zelda will probably stay about the same; they will enjoy more DDDs, but the rest of the changes to the metagame they probably will hate.
- Bowser, Samus, Luigi, and Mario, as stated up higher, will be hurt exponentially by increased number of DDDs.
- Ike will probably be no better or worse off on average. His top tier matchups are still consistently against him with or without MK.
- Peach will probably be more viable.
- Increased Marth play will reduce the viability of Ness and Lucas, especially Lucas.
- Without surprisingly good matchups against the top character, Yoshi and Jigglypuff will drop sharply.
- Pokemon Trainer's viability won't change a bit.
- Link and Sonic will certainly be more viable, but still low tier.
- Captain Falcon and Ganondorf will be slightly worse off than they already are, mainly Ganondorf.
By my count, removing Meta Knight has a positive impact on 12 characters in the game. None of them would change tiers except Toon Link, who will probably go up to High Tier regardless of banning Meta Knight. Meanwhile, I count a negative impact on 15 of the characters in the game. None of these characters should be impacted enough to change tiers either, although I could see it contributing to a bigger picture decline of characters such as Kirby or Luigi if they go down for other reasons too.
That's my 39 cents.