Quoted By:
Smogon's battle sims are bare bones. They replicate a very small part of the games (Link Battle, Battle Spot, Battle Stadium, Battle Tower, whatever). This very small part is also something that only appeals to a relatively small, albeit passionate, percentage of the Pokemon audience.
The vast majority of the people who buy Pokemon are happy to see the new evolutions and complete the Pokedex, maybe go a few rounds at the Battle Tower, and then shelve the game with a few dozen hours put into them.
This is very different from the fan games where you play as a boy/girl/other from Starting Town and you meet Professor Tree and you choose from Grassdog, Firedragon, and Watersnake and get a Pokedex and go on a quest to explore Devianarnta and get all the Pokemon from Bulbasaur to Sombredge for a total of 996 Pokemon not counting the Devianarntan forms, 50 Dark/Dragon/Fairy Megas that Game Freak didn't include for some reason, and yes all of the Mega Flygons.
This is what 90%+ of the Pokemon fanbase goes for when they buy the games. They are not going to buy the games, watch the game load on their handheld, and ponder the ramifications of the new timer system or the nerfs to pinchberries or whatever.
