They have this system called Fatigue that was built to stop people mindlessly grinding out one skill. They didn't tell anyone about it until they played so people got upset.

The problem with it however is that its all built on misinformation and exaggeration of how the system works.

The game gives you 8 hours of grinding time per week per class, after the 8 hours you start to get experience debuffs. People assumed that the classes were unchangeable as they were in 11 but that's not the case. You change class as easily as you change your weapon, because that's exactly how you change your class. And doing things like playing another class, doing quests, crafting and even walking gives time back to your counter on the depleted classes.

And you can use every skill you learn from your class in any other class, meaning you can be a Warrior Priest Blackmage Boxer with absolutely no downgrade to any of those.

You have character level that decides you HP, MP and other base stats, and you skill level, which is defined by your classes. The entire system was built to allow people who dont play that often the full experience of the game while giving players who do play a lot much much better, well rounded characters.