Stalin's (and coincidentally Rosa Luxemburg's) critique of this position was that it would strengthen nationalisms of national minorities and their nationalisms would be just as hostile to socialism as Russian nationalism. In fact, this difference of positions was driven by differing experiences - Lenin worked in predominantly Russian groups and mostly fought against Russian nationalism, while Stalin worked in Caucasian branch and fought local nationalisms there.
Actual Soviet policies were a compomise between positions of Lenin and Stalin, with great linguistic and political autonomy for national republics, but with military, educational and most economic questions being decided by central authorities,