During the 1930s the USA was manufacturing products on the assembly line, Germany concentrated on precision and close tolerances with small factories. This lead to very fine but expensive products from Germany.
Leica was, with other Germany companies, making cameras that last. So pros went with Leica as a tool that would not breakdown. I guess now Leica has gone from tool to accessory.
An aside:
These small manufacturing facilities in Germany made it hard to bomb them out of business in WWII