To deliver on the expectations carried by the Baldur's Gate series name with an experience that is relateable to the series, and which resembles it rather than DOS2.
Well, see there you have it. When I hear "Baldur's Gate", I think D&D (because that is what it is/was supposed to be based on). And to me, what Larian has done with DOS2 is more true to D&D than BG, even without the trappings of races, classes, items, etc. in D&D. Yes, maybe they could have called it "Faerun Adventures" or some such. But, I don't think the Baldur's Gate name evokes in everyone what you think it does. For some people, it is that specific game; for others, it just says D&D.
As an aside, I wonder if the FF7 crowd is in an uproar over SquareEnix's decision to go RTwP with a classis game that was TB in the original.