Frequently when we include a lot of data we find it helpful to divide out the data to make it easier to digest. Folders could be really helpful in helping visually divide out the data. One suggested use case that people wanted was to have review information and reference information separated so everyone knew what was being reviewed with the package.
In 9.1 you used to be able to create collections in the package which at least gave you another table field to sort/divide out the data but this went away in 10.0 when Managed Collections were introduced.
