I used to like it when it first came out, but after completing FF7 for the first time a few years back I understand and even agree with why it's so hated. Even setting aside the fact that it doesn't make a lick of sense unless you've played the game, it's the ultimate nostalgic cashgrab that was 100% made for the money, no different than the notorious straight-to-video Disney sequels. It just went through the motions without doing anything new in terms of story, character development or lore, and it's even worse due to the majority of the game's beloved cast being shoved into the background to make room for three uninteresting, nearly identical villains with the same personality. At times it even detracts from the original FF7; it almost seems after playing the game for over 40 hours you never accomplished anything at all, since Sephiroth is destined to come back and probably still could come back at any time, and the Shinra corporation that had caused so much damage the planet is still in operation.

Basically it just had no real reason to exist besides making money off the fans.