> purely ideological by nature; not against ethnicities, cultures etc (those were in fact actively preserved) - Stalin himself was from a tiny minority nation of Georgians.

It doesn't matter what the official stance was, what matters what happened. My own relatives were sent to Siberia for being ethnic minorities, despite that they fought for the reds with the russian troupes in the finnish civil war. You can make excuses as much as you like that it wasn't because of ethnicity but reality was that ideology didn't matter back then. People are hateful by nature, especially to foreign cultures, taking away the lands that feeds your children and sending all men in your family to Siberian death camp doesn't sound like preserving any minority culture to me.