Why are categories required for Products and Service line items as part of "My Products and Services"

When adding a Product or Service to "My Products and Services", adding your product or service to a category is a mandatory requirement. Why?

iKhokha believes that many Merchants want to provide structure to the ways in which they work. Part of assisting our Merchants in achieving this is to help provide the option of classifying Products and Services into different groupings or categories. This means that when looking up a particular product or service to accept payment for these, it makes it easy to search through the category hierarchy and select the correct item when adding this to your invoice. 

Also, when looking at reporting (a feature still to be completed), you can view performance of your different service / product line items based on how they have been catalogued, which assists in better understanding performance trends of these items over time.