Since the house was located near the town walls, this would have been a less wealthy burgher family. The richest burghers would have lived in so-called ‘beer court’ houses around the town square.
The working hypothesis is that the house was destroyed during the conquest of the city by the Hussites in 1427, when Hussite forces campaigned in Moravia and Silesia. Several independent historical sources mention the siege and conquest of the town, including the massacre of some of its citizens.
The first time this happens to you – you find something amazing because people got massacred or what have you – it can be a very disturbing experience. But most of us get used to it. Great stuff almost always ends up buried because somebody died.