The sheer fucking hubris of it all. The unexamined and unjustified hype wave. The "influencers" peddling the damn thing with naked cynicism. The recycled maps that often just took the same assets and tilted them sideways. The laughably bad QA allowing almost anything to be put in the chat box.
The way it just... stopped being relevant.
That is all. 
i liked how they made this sandbox pvp mmo where 95% of the content is players killing each other but then realized that testers were bored by the lack of content and then failed to pivot towards being a theme park mmo
It'd be like a Disneyland-style theme park where most of the areas were the same structure rotated slightly.