Administrators should not be able to login from the wild for security reasons. This is something Unix and later Linux got right up front. If you want to become a super user or administrator you need to do so after you have gained access to the target system. You still see people doing all kind of stuff to overcome this "limitation". Don't do it!
Nowadays everything needs to be accessible from everywhere, JSON services feed Web Applications and native mobile applications. The trend will continue with the Internet Of Things (IoT), wearables, you name it. But we cannot forget about the basics: An application administrator should not have access to the application from the wild. In fact several other roles should better be restricted to have access to the application only from internal networks. Exposing too much power publicly (even if strong authentication and authorization mechanisms are used) is a vulnerability that we can avoid if we are willing to sacrifice usability for privileged accounts.
The Administrator does not need the same level of usability as the rest of the users. Higher privileged accounts might not need them either. Be wise about IP authorization.