According to the article I linked to, the ambassador to Germany was challenged in an interview about Bandera's antisemitic views (apparently academics regard it as undisputed that Bandera did hold antisemitic views). And the ambassador to Germany said:
That is the narrative that the Russians are pushing to this day, and that has support in Germany, in Poland, and also in Israel
I don't think that's the same as Holocaust denial. But in any case, Zelenskyy thought the comment wasn't acceptable, so he fired the ambassador. Anyway, you also said this:
if the right wingers want to kill each other over which great power gets to extract some minerals, I see little reason to take sides
I guess my view is that countries shouldn't be invaded. Unfortunately sometimes an imperialist power (e.g. Nazi Germany, or Putin's Russia) decides to invade its neighbours, to gain more land, and sometimes to try to suppress the population of its neighbours, or ethnically cleanse them.
I guess I do take the side of wanting Ukraine to successfully defend itself against Russia's invasion. Ukrainians should be able to make their own democratic decisions without the boot of Moscow forcing them into making decisions they don't want to make.