Yeah, well, that would seem logical… but in reality, facts contradict this view.
- FFXIV ARR did have some glaring exploits server side (SQL requests not being checked…) resulting in 380 billion gils created out of thin air, insta-level 50, teleportation hacks and whatnot. Hacking to this level is unprecedented in a 2010's AAA MMORPG.
- This game is plagued by RMT, much more than many others (WoW included, which would be the primary market for RMT), and this has more to do with the way they set up the economy (creation and destruction of gils, namely) than a supposed client protection which, again, was useless since the servers were not protected.
- From a computer science standpoint, empowering a client in a server-client architecture doesn't mean the server doesn't perform checks to validate clients inputs and requests. These are actually two separate things, so to speak. It's a matter of choice, consistency, and to put it bluntly, it's about making a smart design. In this case, the current design fails to protect the game in terms of security while failing at the same time to give a proper experience to the player: security isn't better, sync is mediocre.
So, no, we don't get to blame hackers and cheaters because the problem at hand (sync) lies not with them (every game faces such threats) but with the solution, or lack thereof, implemented by SE (whereas many other games manage these issues much better, and this is vastly documented after more than a decade of practice of massive online games).
