You know what? I'll give you four.
1) Pokémon is ill suited to a massively multiplayer structure.
2) A server based, Online Only game runs directly contrary to the roots of the series and unique appeal of portable consoles
3) The primary demographic can't support a subscription based game and going free to play is entering a mind-boggingly crowded market.
4) Everything you want from a Pokémon MMO is already featured in XY or stands within reason to be featured in ORAS.
1) How can a franchise be I'll suited to an MMO structure? Could anyone have guessed it would lend itself to a keyboard typing structure, a puzzle game structure, an art game structure, whatever the hell Pokemon Ranger is? The universe and lore is rich enough. What do you mean MMO structure? World of Warcraft? Actually asking I'm not sure what you mean by it.
2) It being different than the past == it shouldnt exist. So every Pokemon game should be offline only on handhelds and follow the formula of the mainline entries? This doesn't equate it to a bad idea at all. In fact. THAT is a bad idea. Who cares about roots when developing a spinoff/new genre?
3) Wizard101, Club Penguin, Neopets, that Disney game. Dude its jot a stretch of the imagination to think Nintendo could pull it off. And thats ignoring that it'd be a different game entirely, possibly allowing the targeting of a different demographic.
4) Literally zero of what I want a Pokemon MMO for, which is a huge world to endlessly explore with my friends, is available in XY, and definitely won't be in ORAS. Multi Battle mode in Battle Maison is all the co op we have. Again, you're projecting what YOU THINK that OTHERS think and attempting to dismiss it.
These are your reasons why a Pokemon MMO is a terrible idea?
The issue comes from the "shared game world" element. Specifically, how wild Pokémon encounters are handled.
Imagine for a moment that you're playing a massively multiplayer version of RBY. You get to Viridian Forest and decide to catch a Pikachu. You're having having no luck, but you see another trainer battling one! So you swoop in and catch it. YEAH, NINTENDO WILL LET THAT HAPPEN.
So only the trainer who initiates a battle can catch a wild Pokémon. You see that trainer about to catch a Pikachu and decide that "if you can't have one, nobody can" and faint every one they find until they give up. YEAH, NINTENDO WILL LET THAT HAPPEN.
"Trainers cannot interact with another trainer's wild battle." THEN WHAT IS THE POINT
Dude you're literally believing that you KNOW (in your imagination) how a Pokemon MMO would play and critiquing its flaws. Lol wut? You might as well be saying "my ideas are dumb it wouldn't even work!"
Pokémon battle mechanic is turned- based whereas MMO is real time, If a Pokémon MMO is ever made it would have be part of the spin-off line and not part of the core main series and watered down so it doesn't eat into the main series sales.
MMOs are not real time. And yeah it'd be a different game. If I can be mean for a moment, the same way you guys think an MMO based on Pokemon would be a dumb idea, I think you guys assuming it would be the same exact thing as the handheld games, and then proceeding to use that as reasoning for arguing against it, is dumb. Really dumb.