I think it has to do with the demand patterns of Americans. In the U.S. people tend to go for the latest electronics with the most amount of spec possible but don't value quality as much. U.S. middle class has enough money to continuously spend on spend on high specs electronics but won't go for the high-end goods that have the best quality overall due to the price tag (I don't blame us).
Another huge factor is that Japanese-made electronics strictly follow Lean 6 Sigma principles (heck they are the pioneers). When you look at how other countries like the U.S. and China try to adopt Lean 6 Sigma, you don't see the success as you do with Japanese companies. The reason maybe due to employee culture and how corporations approach quality. Many of these manufacturers are now MNC (multi-national corporations) and it take a lot of work and time to successfully implement Lean 6 Sigma in your permanent business operations and culture. You saw what happened with Toyota in the late 2000s and the failure of quality. They expanded too quick without proper planning and incorporating Lean 6 Sigma in to manufacturing and business processes. This greatly reduce their quality and brand name. The same can be said for a companies having factories in China. Heck I did a paper on how Chinese factories did a piss poor job in implementing Lean 6 Sigma. Basically what @
Kritic was stating earlier.
At the end of the day it is about the consumers wants and profit maximization
Just my 2 cents.