Everyone has some pretty interesting arguments about why this should/shouldn't be banned.
Some people see it as a technique that should not be banned. Why would you take away a technique from a character who's barely at high tier? If a character like Fox or Marth had this, it would be a different story. Also, this technique apparently isn't broken because it isn't winning any nationals or major tourneys.
Personally, I don't think wobbling should be allowed in any tournament. This technique will ALWAYS lead to death from a single grab at an extremely low percent, and is not difficult to perform. The only comparable move to this would be Jigglypuff's rest, but there's a major difference. If jiggs misses a rest, it can mean death for her or at least some major damage depending on the opponent's character. Even if Jiggs lands the rest, she will still get punished after the opponent respawn's depending on the DI of the rest. It's a high risk, high reward move. For the IC's, they will have no punishment (or very little punishment) for missing a grab. Basically a very low risk, extremely high reward technique.
At professional levels of play, players are capable of using their mobility to avoid being grabbed when Popo and Nana are synched together. This is why even the best IC's players do not win nationals when wobbling is allowed. However, at mid-lower level tournaments where less skilled players attend, someone that knows how to perform this technique correctly is likely to win the tournament. Someone like Wobbles will most likely not have a drastic change in tournament placings whether wobbling is turned on or not, because the players that are able to beat him excel at the ability to avoid getting grabbed when both climbers are together. However, a lesser-skilled IC's player with wobbling turned on will result in much more drastic changes when he fights another apponent. Most likely, he will be able to beat a lot of people who would've beaten him if wobbling is turned off. Even if the skill difference is large, he could still win almost solely because of wobbling.
Yes, in order to be a very good player you must learn how to avoid getting grabbed, but at lower levels of play, this just isn't fair.
Anyways... that's just my opinion on the whole thing. Please don't bash me for providing my input on the topic lol. Just trying to share my thoughts.