Can someone (politely) explain to me why this is actually a bad thing? Since afaik without knowing any details of "the plot" how is it possible to say that this is good or bad? Surely it depends entirely on a mass of writing which we have not seen and only have vague speculation about? I can see ways in which party locking can work fine, and ways in which it might be jarring, but can't make a judgement until I see how it is implemented. It might be bad and it might be good - so as it stands I only have an opinion that if writers have an idea they should have the strength to commit to it.
My take on it as that people don’t like this approach to replay ability due to locking out content from what might for some/many(?) be a single play through.
I also think it stems from the fact that DoS2 didn’t do it very well. I on the flip side argue that people with clear agendas hanging back in your camp waiting for Tav to get a move on makes little story sense so why shouldn’t they leave?
However I might be naive in the sense that I would like to think these characters play a part in the narrative another way and that other party options might become available to me in later acts. I think many don’t believe Larian will take this approach (or even like that idea, preferring the mass effect 2 style where you just rotate people in and out and experience the whole story as they see fit).