I mean his answer is pretty good. I don't see much of a need to clarify. I'm happy with what he answered, but since you asked (guessing you don't know what I meant):
Fun is highly subjective, hard to explain. Generally fun in an mmo/rpg is achieved through engaging your opponents in fair, challenging fights (where winning or losing doesn't determine the quality of the fight), build a toolset and then getting to use it in the way you want, customizing your character in the way you choose, immersing yourself either in the world or your class or the things you're doing.
Now of course there's the other side of the coin, the "esports" way of fun, which is overcoming adversity through effort, which is the one accepted here. Of course it has its own appeal, but there's a huge disconnect which makes this place niche, which is that in order for a clean slate for challenges the arenas and setups need to be equalized to the highest extent possible. Unless you strip every class off its basics and then smash them all together until they're as similar as possible, you won't get that in an MMO. Warhammer comes fairly close since you have "mirrors" and there's no huge range of gearing/customization options, you reach rr60ish fairly quickly and entering into sov territory is relatively easy, so character setup tends to fly out of the picture, but you still have classes. This is also usually what long-term/hardcore players of an MMO tend to want, since it stretches the game past the point where you've tried out everything and its time to quit.
The general "fun" aspect of an mmo/rpg is pretty finite, if there's no endless challenge at the top you're done once you've tried everything out enough.
It frustrates me that people don't actually UNDERSTAND "fun" and respond to me with other stuff, but I totally understand why this game leans the way it does. You're faced with two choices here - either plugging the leaky boat as much as possible and taking it as far as possible with its current state, or you opt to repair it on the go, somehow figuring out how to find materials, potentially getting much farther but also risking to sink immediately. Alright maybe the metaphor went pretty far, but in literal terms you either prolong gameplay for the hardcore crowd as much as humanly possible or risk boring the hardcore crowd and attracting newcomers far, far better, but if the newcomers stop the whole place goes down very, very quickly. They chose one, I might not agree with it (I still maintain my point that 700k people at launch and the current massive interest in TW:WH, as well as huge vacuum in the MMO market means this place can go way up, but its my opinion only), but its a pretty understandable choice.
