Landscape/Site/Time

After listening to Mr. Brook's lecture, I wonder how could a great architect make such a mistake in terms of landscape? I'm speaking of the Farnsworth House by Mies van der Rohe. I know everyone makes mistakes but why build a home with a lack of understanding? Do you think that landscape was a concern of Mies and his team? Was it just a bad mistake? or Do you think landscape is an important element in the eyes of an architect?

Weathering/Shadow/Memory

Why is it necessary to understand how a building weathers? Nothing in this world really lasts a long period of time. Our world isn't about being frugal. It's about buying new things when something gets too old or breaks. In theory, if the building is going to get old, then why bother about understanding how it weathers? Can't it just be refurbished if a little mold grows on it anyway?