Except that at the time storage was a major issue (especially storage that was available everywhere, not just in your mog house), so people bought the token for the storage. Items currently on the cash shop are nowhere near as valuable as the storage was back then.
A minion that does nothing vs adding a good amount of storage .. Guess which one most people would rather spend money on...
Not to mention, games these days are WAY more expensive to develop than 10 years ago, yet subscription prices have remained mostly the same. Obviously they're going to look at ways to generate additional income.