Well, it beats making them into the world's most complicated airplanes as with the space shuttle. SpaceX has proven that they can do vertical landings of the first stage intact onto both land and a seagoing barge; after a trip out of the atmosphere and to about 1/5 of orbital velocity but not into orbit. They plan to do a parachute-less vertical landing of the Dragon capsule after a heat-shield re-entry. That turns out to be far less expensive and complicated than a space plane. It does turn out we need a lifting body for much larger vehicles. It still doesn't have to be a plane, though.
We don't need wings.
The computing field is always in need of new cliches. -- Alan Perlis