I am not an expert on these matters, but I would imagine that the process for legally obtaining data from foreign countries is both more difficult and more public (a National Security Letter would have no teeth in Germany). Additionally, Germany has a better reputation (perhaps unearned?) for privacy rights, especially as the greatest pillar of the liberal EU, and because when the NSA bugged Merkel's cell phone they soured the intelligence relationship considerably.

I live in Germany. It appears to me that the outrage from the government was largely theatre for the public, than serious. There is an election coming up.