>>55006069This isn't the case at all, HeartGold and SoulSilver have been universally beloved since their release. And they weren't even released until the tail end of BW's development
The discourse surrounding Pokemon leading up to BW was that the series had grown stagnant/repetitive. BW sought to be a superficial breakaway from many established trends of the series without having to reinvent the gameplay; unfortunately for Pokemon, BW's release eas met with the absolute nadir of the franchise's popularity and cultural relevance. It was after these games and the prelease season of XY where Pokemon went back to the well and began using '90s nostalgia to market the series, which was incredibly successful and still defines the series today.
While some longtime fans complained about 'pandering' with the release of Pokemon Origins and the reveal that Charizard would get two Mega forms, it wasn't common complaint until after the release of XY, and even then it was contentious among fans whether or not reliance on nostalgia was even a bad thing. It was after the release of Pokemon GO - and the resulting eagerness of the series to capitalize on its popularity from SM onwards - that longtime fans started "hating KANTOOO."