Maxperson
Morkus from Orkus
Nobody is saying the DM should not control the NPC's. We're saying that this one specific NPC, that only impacts one PC and no other PC can ever interact with, gets taken off the table. Infinity-1 while smaller than infinity is still pretty damn big. Losing control of one NPC and making a player happy seems a pretty small price. Claims that this is going to ruin the game for the DM seem a bit overblown to me.
Well, that's wrong. The NPC impacts the Warlock, yes. First, it also impacts every other member of the party, as typically the rest of the group will aid the warlock with whatever tasks come along. At the very least, even if the warlock does the task alone, the group is impacted by the lack of the warlock for the length of the task. Second, infinity -1 is still not infinity and if the DM doesn't like the loss of NPCs, he is being forced to play a game he doesn't want to play. It's about the principle, which does seem overblown to you, because you don't care and therefore are failing to understand it.