In this particular case I'm pretty willing to give the devs the benefit of the doubt that more space will be coming and that the real drawback has been a combination of the background code and the UI panels not necessarily supporting showing more tabs/longer lists etc.
I find it hard to believe they wouldn't want to sell more shared bank space if they had the capacity to, considering how many DDO points 10 more slots is priced at.
Sure would be nice if when they give us more they double the space everyone already has available in the shared bank and half the cost of buying more, considering even 10 slots for half the current price is laughably high.