Pokemon should be an AAA franchise. I don't know whose to blame for it not to be, but expecting it to be, given the size of the series, is perfectly reasonable. The fact that the games don't have an AAA budget or presentation makes them an anomaly not only within the gaming industry, but within the entire entertainment industry.
This is why I said they've conditioned people to low expectations. You say sales are indicative of fans liking the direction, but I say it's more that the franchise is basically too big to fail. There are always a large list of features that are dropped between games, some because they didn't pan out well, but other largely because Gamefreak simply didn't want to reimplement them or felt they weren't needed. People buying the games regardless doesn't mean they're okay with these changes. If anything, it shows how they've come to accept losing features as a possibility, aka being conditioned to have lower expectations. Old fans that are turned off are easily replaced by new fans because Pokemon still remains a largely unique experience in the realm of gaming. The only thing close is Yokai Watch and that isn't going to supplant it anytime soon, and realistically, ever.