It is simply the game. It has nothing new to offer. The code itself is barely new-age, offers no kind of adjustments directly to the game itself (talking about new races, new regions (islam, not the arabia bullshit), new skilleffects, new things from scratch).
E.g. The sidescroller Dragonica still has some pserver stuff ongoing, even gpotato shut down his servers due to lackluster and lack in customers (payments, upkeeps), but why people keep playing the pservers? There are tools written fron the exposed C++ code, where you can literally conflict with each section from and within the game. Creating new costumes, new skills, even editing maps and creating new environments. Same goes for Lineage2 and Aion. Lineage2German, a pserver which is still up since 2007? Hell, they are adding more and more stuff to it, new, unseen stuff. Not the regards of "updating server with events", no one will care about repetitive bullcrap after a while, since you are trying to resell the same crap wrapped in some different coverage.
It is just the game. It isn't manipulative at all. Just basically editing procedures won't cash your ass up to the heights like the owner from ecSRO was profiting well (where he never updated the server, it was just new, something unique, that was just fine back then).