a) That's a given, but it was never forced upon you (not to say I didn't click on every NPC and read everything). I found the part where Morte gets kidnapped to be pretty lame because of it's 'forced' nature.
b) I said a waste of the players time, not wasteful. That is to say, good quality, interesting to read diolouge makes up for it's complete lack of relevence to whatever is going on in the game. Most of it was in some way contextual to the world at hand, esspessaly to someone like me who knew nothing about the Planescape setting (and little about the DnD world). Compared to the completely pointless and forgettable diolouge you'd get from random NPCs in KotoR (and probably Mass Effect, though I havn't played it).
For example, the Wardrobe wizard would have been fun to talk to even if he wasn't involved in that quest.