Why do Germans at Oktoberfest sing John Denver's 'Take Me Home, Country Roads'?

I have some alternate lyrics for next year’s Oktoberfest.

Almost Heaven
Schleswig-Holstein
Kaiser Wilhelm
Lederhosen fashions!

Life is Old there,
Older than the Zee!
Younger than the mountains
in Southern Germany.

Autobahn
Take me on
To the Place
to Goosestep On.
Western Poland
into Russia
Take me On
Autobahn
I hear his voice, in the morning hour he heils me.
Der radio reminds me of my oath of loy-al-ty
And drivin’ on to Moscow, I get feelin’
Shoulda been retreatin’
yes-ter DAY!
Yes-ter DAY!

Autobahn…