If the NSA doesn't care what the Germans think, why do they spy on them? ;-) [pun intended]
Seriously: The NSA really cares about the BND cooperating with them:
> http://www.danisch.de/blog/2015/04/23/der-bnd-und-die-nsa/ (in German, sorry)
And if, because of a giant public outrage, this "cooperation" will be stopped, the NSA will not like this situation. Thus, indirectly, the NSA cares a lot, what the Germans think.
You still don't understand.
The NSA is here. In my country. With huge installations. Officially. Together with the CIA and US military.
Example:
http://en.wikipedia.org/wiki/Dagger_Complex
We even paid partly for it(!).
Time for them to go home.
The German government is responsible for the presence of the NSA and it has the means to largely end NSA activities in Germany, but not the will.
So it is not just spying on the EU that is being enabled by Germany's government, it is the entirety of the US drone program that is being used across the Middle East and north Africa. This program, operating as it does outside of declared war zones, is very probably illegal under German law.
I highly doubt that as most German laws don't apply to US military stationed inside Germany (SOFA exemptions).