As a business user I would lie my customers to narrow the search by product type.
Typical use case is a mixed PC category with accessories and PC/Notebooks. When browsing such category customer may want to filter by device or by accessory type. E.g. searching for "ThinkPad" could bring mix of accessories and devices in search, this filter would allow to isolate what customer wants exactly.
Since we now expose product type display name to ui it is now possible to provide product type filter navigation.