
Der Spiegel as the choice of Intelligence Services?
Back in the day the intelligence services would monitor the information collection of news agencies like the BBC. Often it would corroborate, and sometimes it was better (the BBC having good reporters, connections, reputation, etc. to facilitate this).
This changed over time to where the amount of information being gathered was next to nil, news agencies would just regurgitate each others information, reporters would never leave their hotels, and many of the stories just came from 'official sources' and were ones that were pedaled by the government spin offices (UK, US, UAE, whatever).
Basically it is easier and cheaper, and offends fewer important people to create an illusion of doing journalism. Der Spiegel is currently seen as one operation that does still do journalism!