Something that I did notice was that the Swiss controllers providing the approach services to these airports did not have a valid licence for that service issued by the German authorities. Not sure if that has changed in the last 4 years. What I do know is that the Germans worked damned hard to make sure that the invalid licence "fact" was never included in the mid-air collision report.
I was of the opinion that the Swiss authorities assumed that the German authorities had all the regulatory responsibility for flight activities in that area, and vice versa. No interest in regulation equals no changes. Remember, if you were to reclassify the airspace, then that would mean more controllers, more charges to the airlines (and that assumes that you could get the approach controllers for that extra service anyway).