Some of this stuff is interesting, some of it is nonsense. From a users viewpoint:
Rolleiflexes from about the mid 1950's have a level of fit an finish only found on Leica M3's, and Linhof Super Technika IV's. Those from earlier or later do not quite make the grade. Also German cameras have an idiosyncracy that most do not think of. The German patent system, that meant that everyone had to work around everyone else's patents, whether that was a good way to design it or not.
Now the Japanese did not care about pattens, they just copied what they thought was good, and improved what they thought could be improved. Their quality of workmanship was "workmanlike" not "craftsmanlike" as the German stuff was. That means that they were put together to work OK, not to be a work of craftmanship.
Some things like that Minolta Autocord focus lever was not a design fault, the cameras were intended to be serviced every five years or so, not to be used after the grease in the helical had turned into glue. Also the camera was not intended to be dropped on the floor. Yashica TLR's were intended to be cheap cameras (in the 1970's the list price on a Yasica D was $50), that they have held up as well as they have is something of a miracle. By the time the Japanese got it right the TLR was no longer very marketable. Also, the Japs did not have a reputation for quality until well into the 1970's, the quality was actually there before that in the stuff intended for export, sort of like Chinese stuff today. Just to give an idea I am currently working on a Yashica-Mat (80mm Lumaxars) from about 1957, and a Yashica-Mat 66 (Yashinons) from maybe 10 years later, the later camera is more cheaply built despite claims that the quality had improved.
TLR's are actually kind of specialized cameras, there are things they do better than any other kind of camera (people, for example), there are things only a masochist would consider using one for (action, for example). In the 1950's the combination of a TLR and a RF 35mm was considered the cat's meow, then 35mm SLR's took over the world.
Anyway, the 3.5E & 2.8E (including the E2 & E3 versions) series Rollei's of the late '50's arguably have the best fit and finish of any TLR ever made. I still regret selling my 2.8E2 Xenotar long ago.