The "lot of Ukrainians" that saw the USSR as worse than the Nazis were the far-right nationalists in Ukraine spearheaded by Bandera. A "lot of USians" were certainly upset at ending slavery, to the point of armed struggle, but that doesn't make them correct, either. Bandera was a far-right nationalist that is supported by the modern far-right nationalists in Ukraine, which is why there's a problem with Nazi brigades like Azov increasing in relevance in Ukrainian politics post-Maidan.

Further, again, the Soviets were unquestionably the most progressive force throughout the 20th century, from supporting revolutionary movements in Cuba, Algeria, South Africa, Vietnam, Korea, China, and more, to supporting Palestinians against genocide at the hands of Israel, to being responsible for 90% of the total Nazis killed in World War II and saving the world from fascism, to doubling life expectancies, over tripling literacy rates, democratizing the economy, and dramatically lowering wealth inequality.

Yes, there absolutely were problems faced internally and externally, and there were mistakes and excesses. These pale in comparison to the deliberate acts of mass genocide perpetrated by Western Europe and the US throughout the 20th century and today, all while the USSR was under constant siege and the Western world reaped the spoils of Imperialism.

Bandera and neo-Nazism are tied to Ukrainian politics. Nationalists are in control of politics, and the Banderites make up the majority of Nationalists in Ukraine. This is a sad reality that must be confronted, no matter what your stance on the modern Russo-Ukrainian war is, and it ties directly to Ukraine and the US being the only countries to vote against this resolution.