I think many people who are physically unable to take a hike (disabled, elderly, ill, etc.) would appreciate a VR system that can closely mimic a real hike.

Also, if a VR system can perform well as a hiking simulator it would be able to realistically simulate things that don't exist, places that are too difficult/expensive for an average person to visit, or experiences that are too dangerous to attempt in reality.

EDIT: For example, I'd love to visit the moon or Mars but it's highly unlikely I'll ever be able to physically go there. A highly immersive VR simulation would be very appealing to me!