It's an interesting point, which definitely goes against how I GM. I definitely love my NPCs, and for some reason I seem to be very good at making/developing very attractive romantic interest NPCs that players who are into that sort of thing really go for. I find the female potential love interest NPCs easiest (I just think "What would I like?"), but it seems about equally true for the male ones. So the players get really invested in their PC's relationship with an NPC. But a big reason for that is the NPC is very well developed with their own personality and motivations. And sometimes this clashes with the PC's personality and motivations, like when the PC hero-emperor Hakeem petulantly murdered allied Lawful Good Archmage Dyson Logos (yeah, named after that guy)
in a fit of pique to get revenge on Dyson's patron King Bronze of Nerath for slighting him. Funnily enough, Hakeem's very Lawful Good Paladin wife Queen Malenn wasn't very happy about that, not to mention it imperilled the life of their son Hasan, who was betrothed to marry the daughter of King Bronze...
