The State of the Game, Potential Rollback/Mass Banning, and all that fun stuff.

It isn't always about economy damage. :/

But it is always about damage in some capacity.
This exploit doesn't really cause any damage whatsoever.

there are so many ways to go about this really. simplest being:

is the attached char a 120 cygnus with X quest done? Y/N
N = Ban

now, i'll be over there waiting for nexon to do nothing.

It's going to be nothing because this is equivalent to the exploit that allowed people to get level-up event items without leveling up.
Nexon could have done the same thing there, but they didn't.