OMGOMG, I love this due to how this parallels with Olimar.
Now, the minor details which probably make MK broken are different, but its funny noting that the main points parallel Olimar's.
This is exactly how Olimar is with a player who is at the top of the metagame; you cannot gimp him if you cannot ever hit him.MK is broken.
1. He has "no" weaknesses.
Before you harp on me for this, MK has no de facto weaknesses against the majority of the cast. As an example, a character could be made that dies in one hit, but has an instant kill move that is garunteed to hit. Sure, he dies in one hit, but that doesn't matter because he'll kill you first. His weakness does not exist, for all intents and purposes.
MK is like this, though to a lesser extent. He does have weaknesses on paper, but for whatever reason, they don't seem to make that much of a difference. It should be noted that the characters that can put up a fight are the ones who can exploit his weaknesses consistantly and effectively.
Oliamr's "perfect camping" outranges all with grabs and smashes. A lot of character can't do anything about it. Except Peach and ROB.2. He has an answer to everything.
MK has too many options that are all above average. Whatever you do, he has an answer to it. The characters that do well against him are those that have better answers. But even that isn't enough. You need have to a fair amount of "better answers," or the right combination. The last option is to flatout have a strategy that can and will work against anyone, assuming the opponent makes a mistake. Take Diddy, for example. If you make a mistake, he will get you with a bannana, which usually leads to a free hit. Everyone has to deal with this. If you manage to beat Diddy, you still didn't beat his bannanas. You can never truly beat the bannanas, just the Diddy who uses them. This is called a brick wall.
This is why MK has 60:40's across the board, and the reason why previously questionable/bad matchups are now shifting. Snake, GaW, and Falco are examples. Once they found a tactic that worked, the matchup changed.
Did you know Olimar's Pikmin has funky priority? Olimar's Pikmin during aerials will always clank, even against other aerials. The only way to hit Olimar's attacks like uair is to attack before he does or to completely outrange him.3. He is fundamentally different from every other character in the game.
How can a character have NO disadvantaged matchups? They either have to be perfectly designed and have absolutly no weaknesses, or they have to have something so incredibly powerful it essentially breaks the game. MK falls into the latter. His certain "something" is that his sword has wacky priority. MK's sword will never actually clank. The only way to actually hit MK is to attack before his hitbox comes out, or outrange him utterly and completely.
MK's sword is like a mobile projectile. Now, it's accepted that projectiles are brick walls. You must get past their projectile before you can actually fight your opponent. Whenever MK does a move, it's a brick wall. Brick walls mean that any weaknesses the character has do not matter, as you are not fighting the character. Once a brick wall is broken down-if possible-or gotten around, you can start actually fighting the character. The problem with MK is that you're hardly ever fighting MK. You're fighting his brick walls. Which-as I said earlier-cannot be beaten.
Now, the minor details which probably make MK broken are different, but its funny noting that the main points parallel Olimar's.