The red army and prior Russian armies have used rape against defeated populations frequently. Russian rule also tried to supress national identities in Baltic states and others. It's valid to hate them for it. It's still stupid to do so in such an open way, depending on the Americans to protect them. Russia may be popular these days, but remember the behaviour of Russia during the boxer rebellion and the massacres of Chinese civilians in outer Manchuria.
The russians were never as gentle occupiers as the Americans are today in Japan.
I've never seen credible accounts about Soviet rape that isn't just from nazi propagandists.
The USSR ended the war owning nearly 100% of former nazi German empire. They had full control there. In contrast, Japan especially only had control of a small portion of China during the maximum advance (and Germany had a slightly larger portion of USSR). The accounts of nazi crimes were undisputed and plentiful from all sources despite the fact Jap or German invaders never made it particularly far, whereas Soviets made it all the way to Berlin.
Sure there was individual events, but the USSR military policing was hardly lax. A fair number of USSR soldiers were dishonorably discharged or even executed just for looting, let alone the serious charges of rape and murder.
There is and has always been a difference between the military forces of the civilized and the uncivilized world, eroding this with historical revisionism is evil.