This perception is divorced from reality. First off, if BBAI was standardized with BULL, all further iterations would require no further work. Secondly, since BBAI is done nearly entirely by jdog, who also works on Revolutions, which is merged with BUG, keeping sepperate versions, and merging it in probably creates more work.
Also with regards to UP and BUG, that I understand, many people play with BUG specifically because it is unaltered, and the UP, by definition alters gameplay (mainly by patching bugs). BBAI on the other hand is altered, the AI is improved. The subset set of players that accept an altered game experience, and would not accept an altered UI would be an order of magnitude smaller then the converse.
Look at the end of the day there are going to be litterally exponentially less users using Better AI if it does not incorporate BUG. Force people to pick between the two, which is the current state of things (or learn to merge python
), and the overwheling majority will pick BUG. Force users to accept BBAI with BUG, or play default (or the UP I suppose), and your'e going to see very few users that would play BBAI not use it because it includes the BUG UI.