Stamping out minority languages and dialects was (and often still is) unfortunately common in most countries. I'm Russian, and my native regional dialect has some minor differences from standard Russian that make it sound a bit more like Belarusian. I remember how in school we had a teacher making fun of our manner of pronouncing words as "kolkhoznik speech" (implying that only the uneducated speak like that). This was in 1990s.