The only time I semi-regularly see Pacification happens is when ST Amon summons first set of slimes that he'll detonate should any of reach him. First set gives pacification, while the second set gives silence. They happen less IMHO because how squishy these slimes are and clueless DF'er mostly consist of two type of players that contributes to the mechanic resolution: player that attack anything close to them, and the player who attacks anything that moves.
The silence from WoD 5-headed dragon on the other hand usually happens more often because while people know to spot and kill anything that moves, there are lesser who knew how to prevent the next set of slimes to spawn & join together creating larger un-killable slime (by standing on top of the poison puddle until they disappear, presumably this is why we get poison resistance buff should we kill the first slime that spawns).
Back to pacification... ah yeah uhh, I guess PotD trap? lmao. Either way I agree they're 'forgotten' in essence...