Cash shop is good as long as they only sell vanity item (or additional storage (more retainer) or optional service like change name, appearance) and they still put a good portion of content / vanity with free* into the game. (today WoW shop is still good, they only sell skin, pet, mount, and boost to lvl 90 + some basic equipment for new lvl 90.(well I get the idea due to in WoW it is not fun to play as low level. It is practically barren. You need to wait hourly just to go into a low level dungeon). Even though they had the shop, they still put lot of cool mount/pet/skin into the game for free*).

But if they sell something which lock a content/class which mean it's time for me to stop my subs (expansion is different). (which is I am really afraid off).