it's pretty much a rip of. Even F2P games i played handle that better.
First of all, FFXIV needs a lot more inventory then other games.

Lets look at games like Aion NA (free to play) - im not talking about if the game is good or not just the inventory.
Each character is one class. and you get like 90 or so inventory space on each. You can have 8 characters for free.

you have a common warehouse and every character has his own warehouse on top of that. It is more then enough.
BUT if you wanna have more, then you can buy more. But unlike SE its a one time payment and stays like that forever.
SE charges for it every month, If the game develops like it does now... what good is all the vanity if you have to sell it/toss it...
Also crafting is way too complex to have so few space.

But well... the servers are already bad, the stabiliy of this "blabla millions of reg. users blabla" mmo... are a joke. If they continue to use it as a cash cow only its gonna hurt them in the long run.
doing basicly nothing for months before the release while server stabiliy gets worse and then charging full for an expansion is yet another bad move from SE...