No offense, but anyone who has a private file server is a pretty big outlier on the distribution of how an average person uses a computer.
Are you saying slow file copying is not a problem or are you just ignoring what he said in order to make a different point? Every computer is a server (you know file sharing via homegroup and the like). My kids and I share files all of the time across the LAN; music, photos, etc. Was Windows RT (or maybe just Surface RT) not designed to efficiently copy files? I'm just asking because I've never owned a Windows RT device.