It's important to us that we are able to filter for "has created password" or "has/has not logged in" as we're doing outreach to our constituency and are forcing them to log in. We need to follow up those who didn't and continue asking they do log in.
There is currently a search for "Last login at" with a fill in the date box. You could choose to search for "Last login at" before today's date and get a list of anyone who has ever logged in. Adding more robust filtering around users and logins is something we will consider but don't have a timeline.