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.
Baldur's Gate 1 and 2 aren't just supposed to be based on D&D - they are based on D&D and calculate rounds in the background of the real-time experience.
It is evident that the Baldur's Gate series name evokes the expectation of something different than a DOS game in plenty enough of the series' fans.
People for whom it merely evokes the idea of D&D obviously do not care much about the Baldur's Gate series and so their opinion on the matter isn't that important, since they don't care either way and aren't big fans of the Baldur's Gate series.
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.
That's not a game I've been following but I'm sure there has been some uproar over it. When I heard about it I thought that it's an unfortunate change, myself. I still do.
But the theme of Final Fantasy games is that each one is a self-contained story in its own world. When a FF is a sequel to another specific game in the series, it uses a different titling, like Final Fantasy X-2. The FFVII remake isn't replacing the original game and isn't claiming to be its sequel. It is a re-imagining of it.