A tool's Public group is visible to all users. Items in the public group are read-only, unless you have the "Edit public" right. Users that have "Edit public" rights on a feature can only edit public items for that feature. Other public items will be read-only. Read-only items are still useful, since users can copy those items to the "My ..." tree group and edit them there.
I have not found this to be the case for OS Provisioning. The goal is to have locked down public templates, but allow users to copy them to their private templates and edit/tweak them.
LANDesk 9.5 SP2.