There are already some die hard Ninja Gaiden II fans calling Team Ninja "scammers and betrayers" for not having nor living up to the "true meaning" of carrying the name Ninja Gaiden Black. Simple version: they're bitching so much because Ninja Gaiden II: Black is not the vanilla version and its Sigma 2 again, but with the gore added back in and the proper currency upgrade system. They have points of there being less bonus costumes compared to either versions, the removal of Ninja Race (a mode I didn't find that fun nor interesting), but it's not the end of the world. Yes, the Buddah and Statue of Liberty bosses are gone from Sigma 2, but no one is going miss them. They added nothing to the overall experience, and Lady Liberty is just a model swap with electrical attacks. The people who love the vanilla version so much can play it to their hears content. There are still plenty of physical copies on the cheap, and the game is still available on the Microsoft/XBOX store, so the original version is widely available on One X and Series X.
Most casual fans and new players aren't going to care about it, so long as the game is good and fun. Which it is. II Black is a great starting point for people wanting to get into the franchise or games. Yes, I know II: Black doesn't have the bevy of bonuses seen in NG04, NGB, nor Sigma 1 & 2, but it's still a great game with replay value and has the best bonus mode (to me) packed in for that version. Fine if you dislike it, but don't rain on other people getting genuine enjoyment for this version, nor care about the missing bonus features from prior versions.