is that why they do it, or is it to show off? We need someone who knows Japanese

Guy in the suit says it's due to space.

CAUTION!

BE AWARE OF BUS SLIDES!

Good question! I've often considered it. Generally Japanese humor is just more physical than ours, frequently crossing the line into slapstick. It's also largely cue based, by which I mean, the reaction is often perceived as more humorous than the situation itself. A standard Japanese standup act involves two people. A standard joke: one guy says something ridiculous, often a play on a misunderstood word, then the straight man corrects it violently, e.g. with a slap across the head, and/or an amusing contortion of his face or body. The laugh usually follows the reaction, rather than the original gag. Solo comedians live and die solely on the strength of their outrageous and infectious physical reactions to everyday situations. I'm using an example from humor, but of course the same case holds for serious situations as well, whether it be politics or cooking. If I were an armchair sociologist (and I am, Ph.d.) I would speculate that rigid divisions in Japanese society create such a tangle of unseen social barriers that a reaction to any situation, no matter how benign, involves a tension-ridden negotiation in the Japanese mind. The clear visual cues that cover all television broadcasts serve as authoritative "'permissions" to react in a certain way. We find them ridiculous, but the same thing is also at play in the West, of course (the laughtrack being the appropriate example in this case.) We can see it more clearly across cultural borders, especially in a situation where one level of cues (here, language) is removed. Philosopher Nassim Taleb recommends watching the news on mute, to note how ludicrous the whole thing becomes without the constant bombardment of language cues, which are usually invisible to us.

Allcaps, you were doing sortof okay until you used the phrase "the Japanese mind". Sorry but it's not 1952 anymore.

It's like that David Blaine show where you mainly didn't see magic tricks, you saw people reacting to them.

I have a theory about why Japanese humor isn't funny.

Up until the 1940s, Japan was a rigidly defined warrior society. Their entertainment was largely dramatic and epic.
Them WWII hits, they lose BIG TIME, their strongest and fiercest men are all dead or defeated, they've had 2 nukes wipe out 2 cities and they aren't allowed to have any kind of respectable standing army as a provision of their surrender. As a result, the society had to shift. Comedy is relatively new to them. America is an offshoot of European culture that's been doing comedy well since before the days of Shakespeare and Moliere. Japanese humor is still rooted in slapstick and puerile sex and body function jokes. We have that too, but as an element of a larger tapestry of disparate styles of humor.

I find it more mysterious that the people seem to be given points randomly. Is it a contest?