Why would Larian do that? They know that fixing all the problems in BG3 would be a gigantic pile of work, which they would not even get paid for. Because if they made a definitive edition people would expect substabtial changes to Act 3. And with the game getting constant praises because of bear sex and horny companions there is also no need for them to invest any work in order to save their reputation.
So they abandoned BG3 and will never go back.
Because they've done it with their past games that received praise (albeit nowhere near the praise they received for BG3) and substantially reworked the final act in the definitive edition. They put in a lot of work without charging for it. As I understand it this was done at the time they released a console version so the company would stand to make at least some money from it, but there would be ways for them to profit from a definitive edition for BG3 as well. For one people would pay if they charged, and while I know they've been against charging for improvements to their games in the past I feel that if they added enough content charging would be justified. Maybe they could add Ketheric back in as a potential companion or add one of the locations they originally wanted to include but ultimately didn't.
I'll also say that they already added a playable epilogue free of charge after release when they received criticism for removing the original epilogue. To your point I believe this is because of the extent of criticism they received for it, but that's why I think the issues with the final act and the desire for a definitive addition that addresses them are worth continuing to express. I don't see it happening anywhere in the near future, but maybe they'll consider returning to the game at some point.
And in terms of the praise the game received, it wasn't for the bear sex or "horny companions." The game has received praise for the writing, particularly for the companions, the acting, the amount of content included in the base game, the amount of permutations and player freedom, etc.
