I was going to ask the same. IMHO Bill Q and Joanna are reading too much into the expressions of these kids (or not enough, in case I am right that they are imitating Jackson’s style). Some among them doubtless find the whole thing a chore, and it would indeed be a bit cruel if they were made to do this all year around. But at the same time, growing up, I had to do similar drills few times a week in school, except we didn’t have the option to dance to Jackson! Nevertheless that’s not the part of school that sucked. The part that sucked was when it was more important for me to accept on face value say Newton’s First Law -- even though it was patent that moving objects devoid of power generation did not continue to move but rather very quickly came to a stop -- than to explain that the law as stated related to idealised conditions, and that material coming later (friction, air vs vacuum, so on) would fill the gap in my knowledge.
—ravi