I think attachable/detachable crutches will be a nice midpoint to allow some walking without hands over very flat ground. Imagine this: Walk around where it's flat with your hands free, then if you want to go over gravel - you pull out the crutches. (Much like Tesla having autopilot-like features over only very flat, well marked roads)
Ekso might already have technology to balance itself and is simply being held back because of FDA regulations and safety concerns. I doubt this however, I think the team at Ekso sees a nice clear road ahead of them and they want to set up roadblocks for competition early.