Actually the inclusion of Finnish was the error! Its inclusion is very questionable, but the language group was proposed by a Finn. That's why I misremembered (former lingustics/Japanese major here). The inclusion of Japanese, on the other hand has been steadily gaining momentum for decades.
Linguists whose focus is on Japanese generally do generally consider it an Altaic language. This includes the most prominent, such as Marshall Unger (under the name Macro-Tungusic). The classification is still somewhat controversial, but I think it's largely for historical reasons. Local Japanese language scholars, who are not linguists, have traditionally subscribed to the view that Japanese is special and separated from all other languages. Modern linguists do not generally subscribe to that view, regardless of whether a proto-Altaic existed or not.
In any case the points about shared cultural, historical and religious heritage still apply. Finns learning English have far more of a shared cultural framework to work from than Asians learning English do.
Linguists whose focus is on Japanese generally do generally consider it an Altaic language. This includes the most prominent, such as Marshall Unger (under the name Macro-Tungusic). The classification is still somewhat controversial, but I think it's largely for historical reasons. Local Japanese language scholars, who are not linguists, have traditionally subscribed to the view that Japanese is special and separated from all other languages. Modern linguists do not generally subscribe to that view, regardless of whether a proto-Altaic existed or not.
In any case the points about shared cultural, historical and religious heritage still apply. Finns learning English have far more of a shared cultural framework to work from than Asians learning English do.