When I am leading a VOD often there are a ton of pugs. I will often designate and ask specific people to cast displacement at times during the quest. This is a bad example on your part because of the specifics of a VOD raid. Displacement is such a powerful spell in there that as leader I feel I should remind the caster and bard to cast it. A better example would be running a 6 person quest in the Vale or SOS area. Displacement and similar buffs are very nice to have but I and other players will not likely remind people to buff except at the beginning of the quest.