Originally Posted by
Alahra
If they weren't stored locally, the game would have to regularly check with the server to make sure your hotbars were current, which would drastically increase the server load. They're already concerned regarding the amount of character data that needs to be verified (which is the current thing delaying the solution for inventory problems), and this would only increase the amount.
I do wish they had the option to save the data server-side like FFXI had, so you could back them up before reinstalls and the like. (You can sort of do this if you're on PC by making a copy of your character data, but it's not exactly user friendly).