When people have been "too polite" with me, I've often doubted their authenticity. Like, are they faking their friendliness while shit-talking me on the inside?
But then I think, hey, it's nice to be treated nicely! Especially if it's a brief, cashier/customer relationship. I think the Japanese understand the business situation very well—we are having a business interaction, so whatever personal qualms we may have against each other, we treat each other well because that is good business.
Great article and I love your illustrations!