Don't get my post wrong, i'm all for rarity on a realm that will not progress beyond its current patch, but there's a dofference between rarity and atrifically low respawn rates.
The exhaust pipe spawns at only one npc that doesn't change location, and the respawn time is unpredictable and varies greatly.
But for something like a mob spawn or an item drop (like hunter spirit animal pets) or mounts are fine, because it requires the player to actively seek that item, this way the acquisition of that rare item becomes rewarding, both the process of looking for it and finding it, but the case of the exhaust pipe is about who can camp the npc longer and who has more faction friends to back you up.
There is no reward is waiting hours on end not moving at all while staring at your screen bored to oblivion, waiting for a spawn timer that you cannot see, only to have someone who just arrived ninja the thing, or gang on you and ninja the thing too, this is not rewarding, and turns the whole quest into a chore that you just want to get rid of instead of an interesting journey with a rewarding result.
I'm not asking for 10 min respawn time here, i'm just asking for increased spawn rate, if it's currently 2 hours, drop it to 1, if it's 1 hour drop it to 30, it's not fun to waste the few hours of playtime available after a hard workday waiting infront of an npc for an item that you may not see any time soon.