Well, there IS smogon who banned Wobbufett since he was boring, not because he broke the game.
Although its interesting that the community seemed to be perfectly fine afterwards, so I wonder...
...
No.
Wobbafett is not currently banned.
That shows a poor understanding of the pokemon metagame works.
Pokemon doesn't ban pokemon (with one notable exception), instead it sends them to a different metagame.
Basically there are these tiers:
Ubers
Overused
Boarderline
Underused
Neverused
Out of that there are 4 metagames.
Ubers
Overused
Underused
Neverused
In each metagame, you are allowed to use pokemon up to and below the tier that the metagame is named for.
Why? Because it was recognized that pretty much any of the members of the higher tiers, when introduced to the tier lower, overcentralize the metagame tremendiously, and the game becomes "play a counter to this, or lose" and there's not enough counters within the tier to avoid removing a massive chunk of the tier from viability.
What this basically came down to is that there were only a very select few viable pokemon (aka, the ubers and a small number of others). In other words, 3 or so pokemon were effectively viable with the rest being basically cannon fodder, creating tremendous overcentralization.
However, it was noticed that within it's own tier, pretty much any pokemon could compete.
So seperate metagames were formed, and this allowed a robust and viable metagame in spite of the fact that there was a very select few pokemon that were viable when compared to the whole.
Now then, the one ban, it was because of an unexpected interaction between powers that basically stalled out the game. I other words, a totally defensive pokemon had to use up all their pp to attack, and the pokemon in question has very strong hp and defensive stats, basically stalling out the game.
This was wobbafett, during the previous generation he was banned because his power had this effect.
However, when two wobbafetts face off in this generation, they can switch out, ending the stalemate, thus wobbafett is not banned anymore.
But... against almost any OU or under pokemon, against Wobbafett the best possible result is both are KO'd, thus he's definitely an uber.
So, wobbafett was once banned because he created a stalemate situation, but not anymore.