There are many reasons that this should not be banned. A ban is a very important thing. For instance, we banned Pit's stage, when many thought that it was fair and balanced. It could have been a semi decent counter stage. It greatly impacted the game in the fact that now, characters that would have had an advantage there no longer do. Say Ganondorf destroyed there because he could not go through the top platform. (In my experience at the stage this is true). Instead of losing a majority of his match ups he could take them there and win. That influences his match ups and eventually, his tier placement.
But the stage was banned and according to the tier Ganondorf is the worst character in the game. Each decision needs thought to have it done, otherwise something could go very very wrong. It doesn't matter how many people it affects and what it might do, what matter is "Is it fair?" Skyworld was banned because of many reasons that factored into a ban. Not just, will Ganondorf be ok if we ban this?
I have seen the Ice Climbers grab a person at 0%, at exactly 125%, the other Ice Climber charged his hammer and Side Smashed him to death (nice job Lain). A similar scenario happened twice more and the battle was over. Is this fair, yes. Have you ever tried the Ice Climber grab? It takes so much skill that after 9 hours of practice I could not do it. Does that make it fair? Not quite yet. Some characters get out of that combo. Marth can Up B at 45%. Toon Link floats out. It can be escaped with skill, multiple characters can get out (MK), therefore the move is fair.
I could end this right now just by saying, If that is fair then the much less important Dedede's chain grab is fair. But I won't.
It just so happens that the tournament with the IC combo was a tournament with the D3 standing infinite was banned. Which I find silly. D3's combo works on few people. The rule is that after 300% of damage you have to stop. So the question really isn't to ban the move, it should be that you are asking the back room to change that rule. It isn't stalling, breaking the game, and it most certainly not MK's cape glitch, those are the only rules that are banned. No character action has been banned.
Q: BUT I THOUGHT YOU SAID THAT MK'S CAPE GLITCH WAS BANNED?!?!?!? YOU LIED!!!!11!!!111!!ONE!!!!
A: No, not quite. This is a direct quote from the back room's rules.
Stalling: The act of deliberately avoiding any and all conflict so that one may make the game unplayable. Running away from an opponent to reach a better position is not stalling, while doing an infinite grab endlessly against a wall is. Any infinite chain grabs must end quickly after 300% has been reached so as to prevent excessive stalling.
Tell me how and conflict can go on while one of the characters is not there? MK's glitch technically isn't banned, it is stalling, and stalling is banned.
No other cheap thing, Pikachu's chain grab, IC's crazy friggin' grab, or hell, Sheik's grab in Melee is banned. So why should this?
Now, for those of you who say that it skewers the tier and such, like Luigi and DK would be higher if it weren't for that move. Well.... Every character would be higher if Snake couldn't snakedash. That skewers the match up and therefore the tier. I would reckon to say that if Snake didn't have that he would have the #2 spot. Falco can boost smash too. Maybe that should be banned to even out the game.
The point isn't to make the game even or simple, it is to make it fair. Fair so that all characters can expand to the fullest of their ability (without stalling). We need that with the lack of Advanced Techniques in the game, therefore we need D3's combo. A ban is a very important thing. Ever since someone mentioned banning MK we have been throwing the word around willy nilly. The game was made to play through these issues and to find ways to beat them, say picking up a different character. Before we just decide to ban something, think about it from all angles. And if you are too lazy to do that, let the smash back room do it, that is what they are there for. Keeping D3's combo legal is the fair way to play the game.