As absolutely stupid as this is, it’s no different than changing the maps to show Denali rather than Mount McKinley. I don’t think you’re missing anything.

As I understand the caption, this is actually the most commonly googled dream type. I’d expect this is not actually the most common dream type per country, because the most common experiences aren’t worth investigating.

maybe it’s more like “type of dream that most commonly confuses and disturbs people in a given culture”.