Nexon's decline in traffic

While true, they don't particularly care because it has no bearing on the server itself.
Nexon doesn't really care how much additional processing and resources the client has to deal with because the individual players have to subsidize it, not them.
They care about overhead to their hardware, which having extra maps and mob life does impact.

A silly approach, really. But it's nothing new from Nexon - they never seem to realize the impact that their decisions have on the actual end-consumer, and how this may end up coming back to bite them in the ass. As I previously mentioned, minimizing client hardware requirements should actually be one of their top priorities. Remember how long it took them to support Vista/Win 7? Dumb. They don't think it's important, yet I beg to differ, as I personally quit for a long period of time because bossing was un-doable on my machine.

On another note - isn't it true that until a player enters a particular map in a particular channel in a particular world for the first time that map does not hog any resources? I was under the impression that the maps/mobs aren't actually initialized until first entry past a server reboot. Afterwards, they remain alive till the next restart. If this is the case, things like Coke Town would not impact the server operation, seeing as no one can get into those maps.