As opposed to siding with the other side that had just also killed roughly 4 million Ukranians before the war started, and also committed many atrocities against the Ukranian people (which contiued to happen as the Soviets retook Ukraine). I'm not saying that joining the Waffen-SS to fight the Soviets is just (and I'm also making the assumption that no other war crimes were committed, as so far, there is no evidence Hunka was involved in any war crimes) but living in a time where he can't exactly Google the death counts the Nazis and Soviets, and having experienced the Soviet rigime's brutality, its not clear cut. Given the information currently available, its entirely possible a lot of his town or family were killed in the Holodomor and he joined believing fewer would be killed under Nazi rule. Given the death counts under Stalin's rigime, its not a strange thought, esspecially after living through it, and not yet spending much time under Nazi rule. It doesn't even have to be that he thought the Nazis were less dangerous to be a reasonable choice. For example, this was already late in the war, so if he felt confident that the Allies would win, he could have justified fighting hoping that neither the Soviets nor the Nazis would end the war in control of Ukraine. I'm not saying any of these is the case, but until we have some evidence that it isn't one of these, its far more grey.
To be clear, I don't think working with the Nazi army is a good thing, the Nazi rigime was obviously worse, but given the information he would have had access to at the time and the still-unclear background, theres no evidence he agreed with any of the Nazi beleifs or actions (other than fighting the Soviets). Until we find something more substantial, its not clear if he was/is the Nazi (ideologically) he is currently being portrayed as, or just someone who feared continued Soviet genocide of his people. We should not assume he is guilty while there is still room for uncertainty. On the other hand, if more substantial information about his motive comes out, or evidence that he was involved in any of the Division's war crime's against the Polish people, than I have no issue with leaving him to rot in prison for the rest of his life, but we should be sure that he was involved in the Nazi attrocities rather than just trying to protect his country from Soviet atrocities.