for crafting its because, apparently not enough people wanted a more complex crafting mini game, they just wanted to get through it to make items. Since the alpha phase crafting has gotten less and less interactive.
as far as the powerleveling, thats not really a gameplay issue. In fact id say with multi monster fights, and the skill systems, the battle is actually pretty entertaining, and in many situations very challenging. Powerlevel is an example of people going outside the challenge and gameplay that is set up.
As far as the single player rpg idea. You are thinking your idea is the norm. Some people play rpgs and forge ahead in battle, completing content when it is most difficult and challenging, and some people level up until they can murder all opponents with insane ease. This is just the difference in how different people want to play a game. Because this is an online game, you get a clash of these idealogies, and strangely each side wants to force everyone else to play their way. There are journeys, you choose how you want to get there.