He can still use core. Find someone he can trust, and get a copy of the blockchain on a usb stick. Then he can use free WiFi to sync his wallet. A pruning node with no signature info ( when SegWit arrives) will save on disk space.
but then you are no longer a full node. so you might aswell just use electrum
Not everyone needs to run a full node, Yes it would be better for the decentralization of the network, but should only be an option when the user can afford the disk space and the bandwidth required to run a full node. A new user should start with the basics and work their way up to the more technical stuff.
We want people to jump in at the deep end of the pool, but they have not learned how to swim yet.