Why does everything in Japan have two names?

I’m exaggerating, of course, but it is noticeable how often it happens:

– Yamada Denki’s annoying tune has a random “Labi” shouted at the end of it, that apparently being its official name

– Haneda is actually Tokyo International Airport, even though for about 30 years it was hardly international at all

– SMBC is Mitui Sumitomo Banking Corporation

– Daimon Hamamatsucho station

etc etc

Another way of putting the question would be why anyone puts up with it – is it just another example of Westerners preferring the myth that things are just one thing or another??