Russia is hardly unique in being selective in its support for the right of self-determination. The independence of Kosovo was illegal under international law, but supported by the United States and its allies. Most of those same countries are now sanctioning Russia for annexing Crimea, even though that was clearly the will of a large majority of Crimeans. Everyone is hypocritical about these matters.

Interestingly, Spain is somewhat consistent here: they don't recognize Kosovo, because they have their own separatist troubles in Catalonia.