The MAJORITY of the player base plays the game to progress through the story and dungeons. A small minority is heavily into crafting and to an even smaller degree is the vanity crowd. SE will always cater to the majority as that is where the profit lies.
No one is forcing people to buy these items. People buy these items because they have the money to buy them and they want them. Quite honestly SE could expand the cash shop to include X amount of gil and items and I would be fine with that to.
