Much of the land (over half I believe) in this country is not registered with the Land Registry, so it impossible for a member of the public to find out who owns it, and very hard even for a government department with its statutory powers. This makes it difficult for a member of the public to take action if there is a problem with how land is being used, and makes it difficult for government departments to carry out their duties with regards land and its ownership. The situation is also widely abused to avoid inheritance tax, by obscuring the ownership of assets that should be taxed.
Land is held by grant from the state. Its our land we should be free to see how it is used.