I agree, ok to do once you figured out the best way to trigger them. Initially though a royal pain.
Not what I would call very intuitive quests at all.
That is because at least the way I view the NV companion quests is that most of them are not shoved in our faces, as the companions may not be considering them as being overly important until you do something or wander across something which causes them to consider the 'quest in potentia' in a more active way.
Take Gannon's for example, he's so used to hiding his origins he doesn't even consider telling anyone else let alone the courier about them until you show him that you won't instantly turn on him upon finding out his origins.
Ed E again flat out can't tell you about his 'quest' until you stumble across the triggering events.
For Cass without your actions, she wouldn't know enough to bring her quest into being without the couriers actions.
Boone again a matter of trust.
Raul again it's the couriers actions which cause him to rethink his attitude.
I admit you learn Lily's and Rex's basically as soon as you pick them up, but for the rest it's your characters actions/inactions which cause the companion quests to trigger or not.