There is a certain very easily and objectively identifiable formula that makes the original BG games what they are, and as such if BG3 significantly deviates from that formula then logically it is not a BG game.
You can not start with a bunch of subjective opinions and end up with an objective formula. Not everyone has the same opinions about what the core elements of BG 1 and 2 are, or their relative importance.
How is saying the Baldur's Gate games are isometric subjective opinion? It is an observable fact. In forum after forum, when fans of the BG games are asked to list the core characteristics of those games, there is remarkable consensus and consistency on what are those characteristics. The formula of the BG games is very much an observable fact. It is people's reactions to that formula that subjectively vary from person to person, including which characteristics might matter more to them than others and including that people's subjective preferences can change over time.
