A lot has been written about this story so I am not going into detail. The TL;DR version is that the City of Munich is planning to ditch the vendor-neutral technologies that it adopted some ten years ago and go back to Microsoft. Steven J. Vaughan-Nichols has written a very good article on why Munich should not do that.
In addition to the points raised by Vaughan-Nichols, I can also see that Munich politicians are ignoring some things that are going to hurt the German economy. The IT infrastructure of the city of Munich primarily relies on three or four core components: an operating system, a productivity suite to create and manage documents, an email service or groupware solution and a cloud service to store and sync files across the organization.
What these Bavarian politicians probably don’t know, or are comfortably ignoring is that the German software industry is the biggest threat to Microsoft’s dominance in these core areas.