| To point #1. That happens still to today. It is a matter of education and resources. Unfortunately, both are low in Brazil. To point #2. Any guest in Brazil will be treated differently during their visit. https://jornalistaheitormenezes.blogspot.com/2015/11/o-carna... has some interesting historical context about Feynman's trips to Brazil. |
It's a matter of conscientiousness and responsibility. Even if there were no signs immediately available, nobody with an ounce of decency would leave a large hole unmarked. Signs are not expensive, if they're not available it's because of a lack of intelligent and responsible acting somewhere else in in the value chain.
As for #2, it's still a lack of conscientiousness. The students should (at least try) to go to their lecture, that the prof should try to give. Surely, a visit to Brazil warrants a quick hop to the beach at minimum but there's no reason people can't do what they are supposed to do all around.
99% of the world's problems would be solved if we all just acted with very basic levels of conscientiousness and responsibility: show up, do the basic work, think a little bit, be nice, don't be corrupt, try to do good work ... commensurate with increasing levels of responsibility obviously, but 'hole diggers' still need to do their jobs with responsibility and a little bit of pride.