System Admins should have the ability to configure global notification settings by Group, Access Level, or even Home Team. Some users/teams/groups simply do not need certain notifications, however those might be crucial for other users/teams/groups.
The only way to disable a global notification setting right now for select users is to manually set and their personal notification preferences in User Settings. And since this cannot be configured as a default setting when new users are added (i.e. when a new user in X group is entered in WF, set these notification rules:...), you would have to manually maintain that as new users enter the system.
Admins should be able to fine-tune default "notification profiles" based on WF's existing user structures in Workfront (whether that be access level, license type, group, etc).
This would be a HUGE help balancing the needs of our various departments in the instance. I can't imagine we're the only organization frustrated by this limitation, so please give this a vote if you'd like to see this feature in Production!