Because they didn't care about Syrian lives. I think that Russia is still hoping that after a victory or a surrender from Ukraine all of this will blow over. I really don't see how that can happen as far as the Ukrainian people are concerned. At best they will achieve a goal and demilitarize Ukraine, but the people will still hate them. Then again, I don't know what Ukraine's public opinion of the west is right, seeing as how they left them out to dry.