>>36600503A respectable but completely naive opinion.
Pokemon games have followed the exact same formula for 20 years; flavor-of-the-gen aside, there have only been two "substantial" attempts at changing the basic formula in the span of these two decades, with B2W2 and then SM. It's not a game series particularly known for its great or complex story or characters. Every gen, there are 4 things that change: the roadblocks (gyms, villains), the maps, the resources (items, moves, etc.), and the pokemon. The basic skeleton of the game remains THE SAME. You play it for the new stuff.
Not every element that changes is equally marketable: pokemon are the most, followed by a draw between roadblocks and maps, and resources in last place, since they're only marketable when they're big and flashy. So if you take out new pokemon, you're missing on a huge source of marketing, and ultimately money.
Sure a new gen without a single new pokemon could be good and sell well, but for it to be that way gamefreak should put some MASSIVE effort on the story, the world and the mechanics, more than they've tried in a long time. Making new pokemon is easier and people like pokemon so it's a win-win situation that could only go wrong if the roster was entirely not to anybody's taste, which is impossible.
