I think this is far too blanket of a statement given the radical diversity of America in most every respect.
Many Americans certainly will go for the 50% cheaper, 85% as good product. And yet America is the largest market for the iPhone, and it does particularly well here. In the not so distant past, superior Sony products - amongst people I know - used to be heavily desired for their quality.
I don't think very many people consider K-Mart to be among the best shopping choices, quite the opposite in fact; ditto Wal-Mart. Being economical doesn't mean they consider it ideal shopping.
It's very difficult to grok without seeing it at many levels for many years. And your counter point is a good example of why. It's easy to point to Americans who have plenty of money and so shop at finer stores. Nevertheless, at every level the difference between cultures is quality vs quantity.
Regardless if you and I shop at K-Mart you can not deny the market share those types of stores hold in the US. Most people who don't go to them associate them with being poor, or unfashionable products. Not because we truly evaluate, or even know how to evaluate the quality of the products they sell. This is why rich Americans are just as likely to buy poor quality expensive products. The measure is exclusivity, or status symbol, which is an aspect of quantity. Successful Americans rarely show off their good taste and fine quality, they show off the amount of money they have.
Whereas a Japanese person will go into a K-Mart or a Forever-21(low price current fashion 'knock-offs') for that matter and look at the stitching and actually judge the quality. There are poor people in Japan, who wold never buy some types of american products because they know that while it's cheep it won't last very long so the net value is lower. I rarely, if ever, see an American make that trade off (especially in business). In a quality oriented society, people actually build skills to judge quality over a life time.
Not every single person mind you, but as a culture we each lean in a direction.
Many Americans certainly will go for the 50% cheaper, 85% as good product. And yet America is the largest market for the iPhone, and it does particularly well here. In the not so distant past, superior Sony products - amongst people I know - used to be heavily desired for their quality.
I don't think very many people consider K-Mart to be among the best shopping choices, quite the opposite in fact; ditto Wal-Mart. Being economical doesn't mean they consider it ideal shopping.