OK. So if the 11 category can go to 99, why can't the top level just go from 00 to 99 as well without being broken into batches of 10 requiring another level.
Because most of the time the 11.99 is in a date series. So, the 11.01 item is probably not referred to much, and it's easy to zip down to stuff you're doing now. But 100 subfolders are too much to actually go looking through, especially if you're trying to `ls` the folders.