This has always struck me as pretty weak. Yes, paying Yandex indirectly results in paying taxes to the Russian government. But people are rarely so dogmatic about these matters. There are lots of despotic and tyrannical regimes in the world, under which companies must operate because people live there who must try to make a living. Punishing the people at those companies because they're obligated ot pay taxes to their rulers strikes me as rather ridiculous.
Kagi is awesome. I appreciate the Yandex results. I'm not a big fan of Russia.