Well we discussed the legend allowance for awhile. If you and your opponent choose to have the "Standard PC match" that's where the cap on the OU and under legends comes in. Sure, they might be countered easily by some Pokemon, but two of those legends can possibly throw an entire teams strategy off because they don't fall as hard as most Pokemon to the attacks they're weak to.
But the main reason is, we're allowing uber battles. You and your opponent can gladly go for an uber match and use Rayquaza, Celebi, Jirachi, Latias, Groudon-sure that might be a balanced uber team, but that's not the point, haha. If you want, I can bring up an idea: We can also set a tier battle seperate to that of the Standard and Uber where either you can battle using all the OU and down legendaries or have a mixed OU match with as many of those as you want. I don't see how it could hurt to have that option so I can definitely bring it up.
P.S. No, Wobb is Uber again on smogon and here. Garchomp, well, yeah..people just have to deal with him. Unfortunately it's only in a one-month ban on Smogon (again) and the rules have settled here yet.