Presently All properties of items get synced to store, which exposes all information at store end users.
Item Master can be managed by different Company differently and accordingly the Company should be allowed to configure the columns of item master (category / description etc) which it wants to display at store item master at the store level.
It will not only help the company using the item master in the manner in which it wants but also helps in restricting the item sync when there is change in the information in other fields which are not configured to be sync.