German is a word that was created by the Romans to define everything on the north side of the Alps. It encompassess Bavarians, Alemanns, Saxons, Swabians, Friese, Angles etc etc etc.
Obvioulsy all these people kept their traditions after the unification into one country in 1840s. Germany is a very young country and so are Austria and Switzerland. Therefore there are strong regional differences and this goes from north to south and east to west.
Similar to many other countries - UK, US, France etc.