Closing Down question

Has Australia gone past the point of no return with 'selling off the farm' and selling our major ports and necessary services? In some countries like Thailand, foreigners and non citizens cannot own land.
Just why have successive Australian Governments seen the need to sell our land for 'pieces if silver'?
Can these ever be bought back? I do not think it will be ever possible.
If one country buys up say 20% of Australian property and 20% of major manufacturing and essential services, when does Australia lose control of it's own assets?