Russia may cite what it likes, but as I've said before, the situation in Kosovo was such that Kosovo's secession was necessary to prevent further crimes against humanity; in particular ethnic cleansing that was almost certain to approach, if not become genocide. There is no indication that any Russian or other minority in Ukraine was under that kind of threat.
What is more, the secession of Kosovo was done under the watchful eye of numerous international agencies, whereas the Crimean "secession" was done with the Russian military and a puppet government running the entire show. To equate Kosovo and Crimea is ludicrous; both from the point of justification and from the point of how the secession was carried out.
It might be one thing if Putin and the Russian parliament hadn't been preparing annexation instruments at the very same time this referendum was being prepared.