They can say they’re being polite toward others but imo, it’s the other way around.
Well, bgill, it is a habit among the older folks and I think it is fading. The young folk don’t honor the old ways much, anymore.
In the spring, the Japanese hang out under a flowering cherry tree and have a repast. The old folks, wearing kimonos, have a some sake and something light to eat, pickles, etc. The young ones, just get drunk, play amplified music loudly and gorge.