Because it is a credibility thing that's why it empowers even more the Russian speaking communities, Kiev acting authorities attempt to murder a leading politician of their opponents and there are no sanctions which reinforce the feeling the Russian speaking communities are under attack, the "western powers" backing a bunch of criminals. Amazingly enough Kiev conducts its business making the very same mistakes Tbilisi made dealing with the Abkazian and Ossetian nations failing to enable the democratic institutions that allows to deal with difficult matters peacefully when they are built bottom up.