It isn't a bad game - it's just not a sequel to DX1. All the criticism the game got could easily be boiled down to the fact they completely abandoned the original games approach, mechanics, UI, etc. I mean, the story itself isn't bad either, but took quite a beating when the game was released... mostly I think because when combined with everything else, DXIW was such a disappointment to PC gamers.
The UI was probably the biggest thing they did wrong, considering that when released it was scaled to take about 1/4th the screen real-estate. It demonstrated the console focus the game had, which was basically pouring napalm on the PC vs Console issue right when it was hitting its most incendiary point, especially considering the way that DX was one of the greatest PC-centric RPGs ever developed.
The DX/DX:IW issue is actually what got me thinking about exactly how different the expectations console gamers are from those of PC gamers.