What will even be the point of playing cart from a postgame/MMO point of view after next month?

Don't shoot the messenger here because I'm just saying what needs to be said.

Once the bank hits we will be flooded with the same hackmons from previous gens and it won't be long until the 6th gen mons are compromised also. Now that the game has already been 'hard cracked' by one person, the hacking community will have a field day once the data hits cloud storage considering I can already upload a .PKM file, change my DNS and nab the hackmon from 5th gen GTS without ever having my DS in the same mile as an AR/Flashcart.

Now whether or not you care about hacks being against 'the spirit of the game', the acquisition and trade of legit mons is an aspect of gameplay and interaction that will disappear once again. Chances are if you don't care for legit mons you may be a battler in which case you got screwed too now that 6v6 support has diminished.

Before this turns into smogon shitflinging we need to acknowledge that a lot of us favored 6v6 even when doubles were made available and before we even heard of smogon. As for the unregulated nature of VGC I'll let the following video speak for itself : http://www.youtube.com/watch?v=xO_1h0z0dbQ

There was no reason not to add support for both when 6v6 is more popular.

tl;dr 6th gen produced a nice looking game with great new mons, but failed to amend the flaws of previous gens and capitalize on the competitive paradigm of the fanbase.