I didnt say it was all, but having a massive shared bank system was not a part of many mainstream MMOs. This still doesnts solve what I said regarding shared banking - you wont be getting any advantage on shared banking other than you can transfer items slightly more effectively than current. Thats it. You wont be getting 'larger' bank slots to compensate, youd end up getting less storage space per account. This would be a detriment to people who run alts for Crafting Purposes.
If anything, anyone who wants a shared bank system, why? What is it you store in your bank slots that you need access to that cannot be mailed? Cause what do people use bank slots for?
Tokens from bosses/raids - will be character bound.
Crafting/Gathering materials - Shared banking will actually hurt your storage capabilities, not help them. Anything that is untradeable will be character bound pretty much.
Glamour Outfits - Would be predominately character bound unless it was set up account wide item (which is already mailed to you on creation of a new character right now.)
Pets - Character bound
Mounts - Character bound
Gil - You can transfer 1 million at a time. What exactly are you spending excessively high amounts of gil on that youd need to have full access to it that you couldnt do by sending a few letters?
Youre not getting a better deal out of this unless you start requesting changes to the above as well. Keeping them separate at least grants you two retainers with 175 slots each, so each alt gets 350 new spots for inventory (not even including saddlebag).
The game is designed around you having one character that does it all. With NG+ coming, the necessity for alts becomes even less significant outside of how a lot of people use them for extra storage or crafters.
The only suggestion I can see having some merit here is having alts have access to one characters house. That I can see being an ok thing.
Beyond that, youre not being punished. Youre just starting from scratch. Thats it.