Even though these servers typically are managed via remote administration, keeping actual monitors available acts as a safety net when remote administration proves insufficient, for example, if there is a networking problem. One common set-up is to have a bank of tiny little monitors, each corresponding to one server in a cluster, with one large monitor that can “tap into” any of the tiny monitors for a closer look.
Even though the default minimum resolution was bumped up to 800×600 for Windows XP, there are still 640×480 devices out there, typically tiny monitors on servers.
Windows still has to worry about displays running at 640×480 resolution.