A new retrospective of the work of architect Mies van der Rohe asks a critic to takes sides. How odd. “You can ask whether Mies was a good architect or a bad architect, an influential architect or not. You can ask whether he has been properly understood and whether he is still relevant today. But to ask whether you are for or against him seems strangely irrelevant, a harking back to half-forgotten battles of an earlier generation.”