In Solutions, each Solutions Folder can be edited to reflect which users can access the solution:
* Logged in users
This level of access control does not exist in the Service Catalog. I would like to control which types of users see which types of service requests. For instance:
* All users should be able to make IT related requests
* Only Agents should make HR related service requests
* Only Department Finance may make Travel requests
Also, it is silly having all the default categories which cannot be deleted. Users will access the system and see functionality for booking airline tickets, when the scope of the service desk does not extend to that.
You can limit catalog item by Requester groups.
Also, while I agree that it's silly to be unable to change them, you can hide categories by deleting or changing all the items in the category to drafts. You can also re-name the categories to use them for whatever you want.