“The past year or two has seen a total and astonishing reversal in the reputation of modernist architects. These days, who but the most blinkered retired actor would refer to Denys Lasdun’s National Theatre as Treblinka? The once mocked and scorned Colin St John Wilson has become a national treasure, knighted by the Queen, whose scion once reviled Wilson’s British Library building as resembling an academy for secret police. How come this change of heart?”