Yes, its a sad truth. It is sad that history is disposable--and it is sad that too many can't understand that they probably will have to reinvent some important wheels.
History endures long after the places it happened are gone or changed beyond recognition. If we needed the places to know the history, well we all know the history of places we've never been.
For many here history is a hobby, a form of entertainment or maybe a living. It's not reasonable to expect other people to indulge our enthusiasms. If they do fine, if not, no sweat.