The ability to walk around something makes it seem so much more real. With vive you can duck below and look under a table, lean around, view something from all angles. With oculus you're limited to seated experiences so it doesn't feel much different than sitting at a desk with a 3d monitor.

Also, moving your character with a controller or keyboard can be nauseating. This is why the best oculus games are going to be "cockpit simulators" or they're just going to have a"virtual screen". The vives ability to move yourself with your own legs keeps nausea in check.

The Vive's entire ecosystem is set up for moving around, using your hands, and really being 'VR' like we've all imagined. The oculus is your head as a camera in comparison.