Just because you don't use it, doesn't really mean no one use it. I know there are a group of people across different world who make use of that content on a daily basis since -cough level 40 farm-
And like AznboiE said there are some stuff there I…
I have a feeling its the same spammers that spammed on a forum in another game that I played. Same set of spam-text although they were stopped by spam filter later. Lets hope Nexon do something about this for their forum soon !
I think it's mostly coins from previous coin-shop events not dungeon-shop events (such as Maple Leaf High) but then I could be wrong. Just a random guess!