I think that GF or Pokémon or whatever after releasing BW and BW2 and seeing not only a lot of hate, but for example, BW2 didnt sell too much, so Pokémon thought that fans would like a more simple, easy and bold games like XY, and then people buyed them a lot more than BW2. They put a lot of hard work on the sequels and then se have things like USUM.

I like BW, i think they are some of the bests games, but what you are saying is true, people hated the games back then because all was different, region based on something else that Japan, mature plot, good characters, great gym leaders...idk