"Europe is diverse enough that you need to split it into quadrants to decide what countries are relatively similar"
The same is true for South Asia, but if you look at it from a western perspective you see the similarities.
There are plenty of similarities across Europe. Shared attitudes to sex, politics, religion..... things like freedom of worship and separation of church and state (laws restricting freedom of worship even in secular democracies like India, let alone the Middle East or China), attitudes to sex and sexuality (and ideas and definitions and identities linked to them - although this is changing because of Western influence, historically the idea of people having a fixed sexual orientation is a modern western one, for example)....
That's not true. To use the examples in the thread, a patient American kid will be much more patient than an impatient Japanese kid.
It seems to be to be a common failing in the west to underestimate just how big differences are between themselves and other cultures. The two cultures I have lived in, despite being Britain and one of its former colonies (and therefore partially anglophone, similar political system, lots of other influences) are quite substation, and noticeable even in the (heavily westernised) circles I socialise in there. The differences would be even bigger if you compare to an East Asian culture like Japan.
Things that are regarded as fundamental concepts, or universal values are often not share (some values are pretty much human, some are not).