Russia looks very much like mainland Europe, it dresses like mainland Europe, but it is not considered part of Europe. This is not a recent phenomenon. Even since the time of the Tzar's, especially Peter the Great, Russia was somehow considered not part of Europe. One of the goals of Tzar Peter, was to make Russia more European, by taxing beards and banning Russian style clothing.
Another plausible pattern is that countries and cultures that use a Latin or its derivative scripts are somehow considered more European than countries that use Cyrillic scripts. Is this causation or simply correlation?
Most of the Russian population lives on the European Continent. The politics of Russia is decided by those living on the European Continent. The Russian Empire has had German queens.
Having said that, the distinction stands, and this effort from the peoples of Slavic origin to prove themselves European continues till this day.
Is this due to the schism between the Russian Orthodox church to the Catholic Church which ruled continental Europe and would decide who became king in the Holy Roman Empire as opposed to the Tzar of Russia who appointed the synod of the Russian Orthodox church?
What is the reason for this geo-political pattern between the peoples of Russia and the peoples of Europe?