If Koolhaas thinks that he’s bringing up some new or heretofore unexplored territory, he’s a little behind the times. There is a tremendous body of literature written about the preservation of memory, of the interpretation of public spaces, and how the choices of what to preserve can be interpreted. I’ll post some further reading, if anyone is interested. It’s an interesting subject, and not a new one. Kevin Lynch’s work, What Time Is This Place?, is a good place to start. Stewart Brand's How Buildings Learn is also thought-provking.
The history of Colonial Williamsburg offers additional insight. For example… The gardens of Colonial Williamsburg were developed based on early attempts at archaeology interpreted by landscape designers of the 1930s. The gardens there influenced the path of landscape design throughout the 20th century. New archaeological discoveries and more advanced scholarship have shown that certain elements of the gardens at Williamsburg are not historically accurate; however, the gardens have become such an iconic symbol of the museum town that they have achieved a level of significance all on their own. Do you preserve the gardens as is, or tear them out and remake them according to current scholarship? You must consider that current scholarship may or may not be perfectly accurate, and consider that, by tearing out, you remove a perfectly preserved landscape from an important era in the history of the town.
Ultimately, I feel that the solution offered up in one of my historic preservation seminar classes came the closest to offering a useful definition of the benefit of historic preservation: historic preservation is a useful tool for managing change. That is to say, a historic district will not prevent change from occuring, but provides a tool for thoughtful approaches to sensitive spaces. The fact that, despite the challenges and complaints, people respond to and desire to live in these spaces, says to me... that there may be some universal principles of attractive places.
It's odd that Koolhaas slams preservation in the US on one hand, while his solution for China oddly resembles... the historic preservation districts he criticizes here.