The only users that can see all alerts are in fact admins, but for non-admins unless they have ownership of an alert they get blank dashboards at least on my install (running the latest and greatest btw. This is a less than ideal situation if this tool is to be used as a central point of alert management for a NOC, Perhaps a better option would be to allow members of groups to see alerts that are routed to their group without assignment or acknowledgement, or perhaps viewing should be separate from escalation; escalate as it does now based on calendars but allow a view all capability for users that can be filtered based on different criteria
Admin/user screen caps taken at same time
The first screenshot shows the filter "All Alerts".
The second screenshot shows the filter "My Alert".
Try playing with the filters and I think you will get the behavior you want.