usage of feature category, feature type, feature

Do you create a new feature category for each virtual product.  Since a feature category includes feature types which include features and a feature itself contain 'Unit of Measure ID','Quantity','Amount','ID Seq Num','ID Code','Abbrev'.  I would expect that the hierarchy is very specific to a particular virtual product.

1. Could someone confirm my understanding?
2. Could someone tell me the reasoning for this design.  Since the variant product has most of these ProductFeature entity attributes.

Thanks in advance

Hello,
Anyone have a response to these questions?
Thanks