I mean, 2nd Edition AD&D was the core of Baldur's Gate 1 and 2. Twenty years later, it makes sense for Baldur's Gate 3 to be based on the current version of D&D (5th Edition). Technology has come a long way in two decades, and it is now possible to make a D&D game that is closer to it's table top counterpart than ever before. They are focusing on D&D fans because it's D&D that provides the core mechanics and it's Wizards of the Coast that allowed them to make the game in the first place.
Hang on a second, why were BG1 and 2 not turn-based as well if holding true to tabletop mechanics has always been their preference? I thought this was about making a great role-playing game first and foremost. WoTC can promote their products without restricting creative freedom to such a degree in my view. Just my two cents.
BG1 and BG2 were both turn based, it's just a question of how to display it. Everything in BG1/2 appeared to be happening in real time on the surface, but all abilities and attacks were separated by rounds/turns. That's why, when you chugged a potion, it would be awhile before your character could chug another. Or if you cast a spell, you couldn't immediately cast another one. Melee fighters had a certain number of "attacks per round" as well.
Now, whether you believe BG3 should have the DOS style of turn based is a matter of opinion. I, personally, see Larian's way as superior, especially considering the affect it has on multiplayer games. The major drawback to the original games was the need to pause to micromanage your team. This isn't a big deal in single player, but playing with friends? Yeah, pausing is hectic to say the least.
