They care if somebody copies their devices really close, and then goes into their market
Years ago, there was a small american company selling PC's that looked 99% like Macs (not Psystar). I forgot the name, but here Apple also went to the courtroom. Same problem here, these people copied not only their designs, but they copied really closely on products that competed directly with Apple's products in Apple's markets.
Apart from that, the Braun products are from the 70ties, and the Braun designed said he was flattered by Apple picking up where they left off.
Interestingly, Polaroid does exactly what you said: When somebody releases something that has the distinct Polaroid picture look, they threaten with a lawsuit. I experienced it up front: One of my apps was rejected from the app store because my pictures in there looked like Polaroids, and the rejection was in order to prevent me from getting sued by Polaroid, which seems to have happened before.