Because the devs are making this content to attract these people, and this content is taking the place of more meaningful content. Not to mention I would have enjoyed another story mode that was actually about the characters in the lore and their adventures and where you actually play as them the way they had it in V. But even if we will eventually get more characters (though the jury is still out on the cultural diversity) we probably won't get the kind of story mode I would actually enjoy because they did this **** instead. I don't want to see how my avatar rises through the ranks and becomes the secret most important street fighter character in the equivalent of a self insert fanfic. I wanna play as the actual character and stop whoever the new bad guy is.
Like, I wanted a story mode in Nick Brawl. But i didn't want a big 3D open world map where I create my own Nicktoon and learn from the iconic characters and blah blah blah. I wanted to see the actual characters in a big story scenario. And minigames are never the answer. Nobody wants to just play minigames on their own for no reason. Just look at The Top 100. I was able to get into fighting games without all that. Purely because I liked the characters and the story and that's all I needed. If we're trying to attract people who need more than that, than we're attracting the wrong kind of fan.