Once upon a time, when computer storage was at a premium, I could see that there would be costs involved in maintaining accounts - these costs no longer exist (i.e., all communications with some programs, such as AS, are all by email). Between mail and storage costs, there were real costs. But each non/low-activity account must cost not much more than pennies a year to maintain. It has to be all about the liability on the books, and a relatively-quick way to show profits sooner rather than later.