Preserving History--The Brutalists

I've lived in Reston 40 years now.  A hot controversy these days is whether a building from Reston's early days is worth saving.  The arguments for saving it are basically the fame of the architect, a prominent "Brutalist" one.

Given my education, I might be expected to be on the preservationist side.  But no. (I'm stealing the image form a Reston Patch post, linked  to above.)  I see no point in preserving all of mankind's mistakes.  I like some modern architecture, but I don't think this building qualifies as good.  The only valid argument for its preservation I can think of is as an example of how misguided we humans can be, how prone to fads and following the crowd.