Because Austria – specifically eastern Austria (Vienna, Burgenland) and south-eastern Austria (Carinthia, Styria) – is where the Germanic world meets the Slavic world, and it’s been that way for the best part of a millennium. During the imperial days (so, until November 1918), Vienna as the capital of the Austro-Hungarian Empire was a magnet for immigration from all over the Empire, but particularly from nearby Bohemia and Moravia, just to the North.
In slav austria windows are just elevated squatting positions! (only gopniks may upvote) from r/slavs_squatting