Imperialism is not an action to be committed on a whim, in the eyes of communists, but relevantly is a stage in capitalist development. As bank and industrial capital consolidate and monopolize, they form finance capital, which seeks to expand internationally and thus the economy shifts from focusing on commodity export to capital export. This is a material system, with definite material causes, not something to be engaged upon at a whim.
The idea that countries would simply be evil if they had the opportunity to is an idealist argument, not a materialist one, and thus is anti-scientific. This is closer to a religious look on life than a scientific one.
Further, as we are placing the Soviet Union in its actual, historical context, nationalities were protected, languages that were never written were alphabetized, and the right of secession was protected. Tremendous development happened, and ethnic minorities were culturally protected and celebrated. There were instances of population transfer, and this by modern standards would be considered barbaric. However, this practice was enormously common among capitalist peers like the UK and US, and neither of them had the same level of thought and care placed into respecting and uplifting various ethnicities.
The only conclusion here is that you either are entirely unfamiliar with the true severity of repressions committed by the west, and therefore the shift to the positive direction as compared to their peers, or are entirely unfamiliar with the sheer care and uplifting that did go on when it comes to ethnic minority rights in the USSR, despite failures like population transfer.
This is why we are pointing out that you do not take a scientific approach to history.