Here in the US, while there are plenty of bad convenience stores, I know plenty larger chain stores, especially between cities (buck-ee's in texas!) where I have eaten some of the best tacos, pizza and fried chicken. Having fastfood chains in a convenience store is also common and the bigger ones always have sitting spots. Not to mention love's, flying j's and other truck stops have even more stuff and the clealiness…
There is close to zero overt racism of the sort you're referring to.
In almost any Japanese customer service situation involving big companies, the smiles and friendly demeanor are mostly a facade for a very transactional relationship.