[calex59]

This is a mound of dirt. If there are no archeological artifacts to find, or if they simply don't want to dig for them, what is the point in spending hundreds of thousands of pounds fixing it?

This is one idiotic enterprise IMO, but whatever floats their boat.

[ApplegateRanch]

what is the point in spending hundreds of thousands of pounds fixing it?

If "we think" it was built spiral-fashion; if "we don't know" how it was built; if "we aren't sure" why it was built; if "we have no idea" how it origianlly looked:

Then how in Hell can "we fix" it?

Maybe they could just follow the current trend of archeology, and bury it in plaster of paris, until "future archeologistss have the knowlege and expertise to properly study" it.