It's all about managing your expectations. You expect a mountain from a hill, and you still get a hill. BDSP are, essentially, improved Diamond and Pearl. They've got faster battle animations, which is my most favorite thing, the Platinum flair the game was given was enough to make certain things, example being Fire Types, more accessible. The new Underground is way better than the old Underground, and I like seeing all the trainers running amok underground, working together to get mining jobs and diglett dust done.
The only thing that I'm not happy about is the lack of XP candies. Because they don't have XP candies, we have to grind XP the old fashion way, and I'll be the one to admit that SwSh have spoiled me in terms of leveling my Pokemon. I very much rather get my Pokemon to level 100, because it feels more complete and satisfying to do so.
So in short, they aren't perfect but they sure as hell aren't bad. I personally feel that in terms of actual bad Pokemon games, I would have to agree that XY are the worst of the maingames, but that doesn't mean they're bad games either.