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?
Different groups of people have different opinions on what the core essence of the tabletop experience is, and individual preferences will influence the design choices made.
I thought this was about making a great role-playing game first and foremost.
It is. Some people don't agree on what makes a great RPG, though.