Well, genetically that's not true; they're mostly eastern slavic. But their thinking was most definitely molded to the Mongol traditions, and they do still think much as they did 500 years ago. The liberal European culture we evolved in the West never penetrated past Poland, despite the effort of Czar Peter.
https://ricochet.com/1214468/finnish-intelligence-officer-explains-the-russian-mindset/
Putin had no Slav features. The Mongol eyes gave him away.