I've worked with Yamaha Music (MI, AV, and CA-PA-products) for 5 years in Sales & Marketing, in-charge of all CIS-region + Russia.
Yamaha is a chiep company with NO respect to its people, Customers/Distributors, or business.

You will never find any logic explanations to its behaviour,

...so far the sales are working only due to Brand, the name.... but it is falling down now, and will eventually collapse-- that's obvious!
The product is also with lots of manufacturing defaults...

Japanese TOP-Management of Yamaha do not follow the basic business-ethics, whether it''s related to Clients, their staff working for them, or even themselves.
The only option to make career in Yamaha is to @*$%& with all the managers, like NIGA4LIFE uzbek is doing. Good luck to her!
Yamaha SUCKS!!!!!!!!!!!!!!!!!!!!!!!!