One of the most popular annual events of the Imperial Household is the "Utakai-hajime", literally, the "beginning of the poetry sessions". Since time immemorial, the Imperial Household had opened the year for poetry with 5-7-5-7-7, 31-syllable tanka created by members of the Imperial and noble households. Since 1879, the best works of commoners have also been included in the event. In selecting the tanka and their authors to be honored at the event, the Imperial Household takes care to ensure that all areas of the public are included in terms of age, gender, occupation, and whatnot. There seems to be an effort to reach out to the Japanese expatriate community as well. It is definitely a Japanese nation thing.
This event, of course, would have little social resonance if poetry were not an integral part of life in Japan. In fact, every general-purpose, national daily in Japan devotes a full page each week to poetry. And not the Walt Whitman, Robert Frost, Maya Angelou kind of poetry, but your kind of poetry. That is, thousands upon thousands of amateurs send in tanka, as well as haiku, the much newer and shorter 5-7-5 version that you are all familiar with (note: this is a gross oversimplification, but it will do for now). Typically, top-level professional tanka and haiku poets sift through the entries and choose the ones to be published, and grace the best of them with brief, individualized commentaries.
Why, then, did we become a nation of poets? Natural selection, if you ask me. And though you didn't, I'm going to tell you anyway.
A Japanese custom that goes back even further than the utakai is the utagaki. The Japanese language Wikipeida article tells you that, on a fine day in spring or autumn, we Japanese used to get together outdoors and eat, drink, and be merry, then start throwing ad-lib poems at members of the opposite sex. (Or so it seems; the article does not mention gay/lesbian utagaki. NTTAWWT.) The recipient of the poem would respond with a poem of his/her own, and so the two would be going back and forth, like dueling rappers, until one of them couldn't keep up and would say, damn, I'm f%&ked. And the loser would have to "submit" and go off into the bushes with the winner, giving the event the air of a Def Poetry Jam with a big fat prize at the end.
This is believed to have been a kind of fertility rite, and it sure would have made for a lot of babies conceived in sing-song. And so it stands to reason that, over time, the better and more prolific poetry genes crowded out the less well-endowed. Geneticists will tell you than a small evolutionary edge will lead to total domination in a geological instant.
In America, of course, the poetic couple would never survive to have children, since, after finding themselves alone in the bushes, working up to an R rating, Jason Vorhees or Michael Myers would show up and ruin the fun.
And that is why Japan is good at poetry, and America is good at movies.
Thank you, Ms. Intercultural communications professor, for inspiring this post with your query about somewhat similar cultural customs in Southeast Asia. The Wikipeida article actually discusses the similarities.