The problem is these people think their sub entitles them to everything the game offers, optional, cosmetic - or not. There can be an argument for pricing (which is high, but not far from the norm), and whether there should or should not be a cash shop in a sub-based MMO,
They could add something where a sub gives people like 100 Crysta a month, and they can use that to buy a new outfit every 6 months or something. That's what Swtor does.