I'm under the impression this is a Chinese vs. Japanese difference. Shoveling food into your mouth is perfectly acceptable in Chinese etiquette but discouraged in Japanese. Accordingly the Japanese cook their rice to clump together so it's easier to pick up using your chopsticks so that you don't have to resort to shoveling.
So what are you expected to do with the last few sauce-soaked grains of rice that would at best be able to be plucked grain by grain from the bowl, and even then would likely slip from between the tips of the chopsticks? Just leave them in the bowl?
I haven't been specifically informed as to either question, but I find that idea surprising, since noodles are infinitely easier to pick up with chopsticks than rice is.