"Why should BA be an exception?" Because it was designed that way. And they learned some lessons from the content and applied those to Bozja. But they're not inclined to spend the resources going back to modify every piece of content to apply every lesson learned. They'd be remaking half the game every year.

Additionally, they probably just simply don't see it as the big issue it's made out to be, as (from what I recall back in the day) JP was absolutely capable of just getting randos together in the instance and getting it done, without exterior programs.

Truth be told, most of the mechanics of BA aren't so bad that Discord is necessary. We just make it necessary by naturally being a culture resistant to working together on the fly.