People purging exploit mechanics are concerned about the standart experience, because if the game releases with a lot of balance issues, or full of "creative solutions" that doesn't link players to BG or D&D 5, it'll displease D&D 5 fans, and Wizards of the Coast and hurt Larian's sales. If that happens, we can all forget about Baldur's Gate 4, and about seing our characters in epic level.
Nobody cares if Larian makes a menu with "Homebrew Rules" putting all sort of shenanigans there that can be activated or not, or if people want to mod the game according to their preferences.
Making the game fun or broken is the job of the mods, a Larian shouldn't waste time on broken mechanics like barrelmancy or high ground advantage.
Putting exploitive mechanics inside a "Homebrew rules" menu in the game isn't a problem, IMO.
Just like they have done with "Gift Bags" on DOS 2 - they can put whatever they want in there.
It can't be done by mods because it's not possible to play coop using them.
My main concern is having absurdities like barrelmancy, outrageous high ground advantages and any other exploitive mechanics as the standart game experience.