You could argue some of the land parcels in question are owned by growing numbers of family members with each new generation, and that therefore it's likely some (even most) owners wouldn't utilize the land. However, it's also interesting to digest this situation alongside Oxfam's report [1] on 62 people accumulating more wealth than half the world's population combined. Zuckerberg owns 700 acres of Kauai[2]. Why isn't that enough?
[1] http://www.oxfam.org.uk/media-centre/press-releases/2016/01/...
[2] http://www.telegraph.co.uk/news/worldnews/northamerica/usa/1...