That's a silly map, given there's no actual authority to define this and the rules are arbitrary.

Here's another map of Western countries: https://upload.wikimedia.org/wikipedia/commons/9/91/The_West...

The definition you're alluding to seems to be widespread within the US, but is by no means the most widespread on a global level.

I think this map is closer to what most people consider western: https://upload.wikimedia.org/wikipedia/commons/8/8d/Westernc...

The term 'west' outdates the discovery of America and no longer has anything to do with Geography. It used to mean western Europe. Now it essentially means western Europe, canada, australia, and america. All of which have cultural roots in Western europe and liberalism etc.

'western' means 'west european and similar', not 'western hemisphere'. It basically means most of europe (now) and the anglo 'new world' countries, though the exact countries involved vary depending on who is doing the defining.