It's obligatory because it's packed with people with no room, and not advanced enough to have enough restrooms, who are set to do farm work. It's a thing of necessity, they don't have the leisure to be modest. Who's to say they wouldn't be? They obviously just got over it because they were forced to, because humans adapt to a lot of things.

Face it, when you think of chinese culture and beauty, you think of what the higher class has produced, and they wear clothing and deficate privately, and this is what the lower class you're illustrating it with aspire to.

If you want to get down to it, you might attribute any trauma to 'societal programming'. I seriously can't believe you're comparing sex to this. Sex, a private thing (generally done clean) where you choose to share yourself with someone you know very well... and being forced to pee in front of a bus full of peers. Seriously.

Trauma's bad, and you know what? Sex can be traumatic even without societal programming to make it seem bad. Oh sure, maybe eventually they wouldn't cry, they'd get used to shitting in front of each other like Chinamen, but that doesn't mean they're healthy for it.

We're not like animals. We don't just shit, we know we're shitting. People know about bathrooms. They know about special isolation and privacy, that sanctuary. They work hard so some day they can have it. Don't dare put words in their mouth when you've never lived that life of squalor.