What is considered Western Europe varies according to source. The CIA does not include Germany as Western Europe, but includes UK, and a subset of Western Europe called "Southwestern Europe", which includes Spain, Portugal and Andorra. On the other hand, the United Nations do not include UK nor Southwestern Europe as Western Europe.
I'm sure in a colloquial sense, most people associate "Western Europe" with "countries in Europe part of the Western world". In this colloquial/popular sense I was refering to, ice hockey is not that popular among most countries. If you don't want to call all the countries in blue "Western Europe", fine by me, it's just semantics, then let's call it "European countries part of the Western world". In most European coutnries part of the Western civilization, ice hockey is definetely not mainstream.
Thanks for clarifying what you meant by Western Europe and hockey.
You are right that in most countries of Western Europe (as per your definition) ice hockey is not that popular. However, the countries in which it’s popular in Western Europe - Germany, Sweden, Switzerland, Austria, Finland and growingly Denmark have a large population for Western Europe and are even more important Economically.
Moreover, the list you originally posted refers to all hockey variants though - not just ice hockey. In most of Western Europe (as per your definition) a hockey variant is popular.
- field hockey is popular in Spain, Netherlands, Belgium, UK, Germany, Great Britain
- ice hockey is popular in Germany, Switzerland, Austria, Sweden, Finland and growing in Denmark.
Also note that I asked if you consider rugby union as mainstream, then why not ice hockey.
Rugby union is popular in Western Europe in arguably six nations: England, Wales, Scotland, Ireland, France and Italy. So that’s quite similar to the popularity of ice hockey in Western Europe.
Then outside Western Europe ice hockey is popular in the United States, Russia, and a lot of countries of Eastern Europe. Meanwhile rugby union is popular in Argentina, New Zealand, South Africa, japan (and arguably Australia and some pacific islands though they usually follow different rugby codes). I don’t think you can say rugby union is mainstream but not ice hockey.