CNG isn't doing every little thing. He won't make Pokemon Contests, increase maximum Pokemon and stuff like that, he's making a new Pokemon Essentials, which still requires you to do stuff yourself. He won't be making a whole bunch of minigames, just a lot of HGSS functions. If CNG put every past and present add-on non-mainstream function then people wouldn't have to do anything for their games and that would be incredibaly lame.
He could make slots, frontier, underground, voltorb flip, contests, etcetera and sure it would be cool, but it would also make every single fangame the exact same and have nothing special about it. I would rather see loads of people make their own unique system and function - how many people would bother if it was already done for you? It's like cheating in a school exam.