IMO, the Pinpoint set is designed as a counter to Armanz & WuKong for Arena fights, specifically. This adds an anti-sheep tool to the tool-box.
I am not going to run the Dungeon at all until there is an event or tourney that I am interested in that requires it. If everyone plays the new content immediately, Plarium does not get any immediate feedback that says it was a stupid idea to put all the garbage gear sets in there. Instead, they get the idea that it doesn't matter that they did that and they can be happy with themselves for not needing to offer meaningful rewards with the new content.