Trading the future of the game for a vanity item to brag about. Because they belive, the money the spend on the vanity item is somehow invested back into the game.

The only way this game will ever develop further is when subscriptions drop and people stop feeding SE money. As they are now, they have absolutely no incentive to keep developing the game, the player base is steady, the cash shop works wonder to get the company extra money and the subscription probably is funding other projects/meeting investers expectatives while the dev team is basically doing "what they can with what they have".