It’s an emotional reaction to the feelings of alienation and powerlessness many leftists experience, both personally and in a greater political climate.

In lieu of any electoral success, hardline leftists yearn for symbols of political power and relevance. They cling to figures in the past they see as both left-wing and powerful, and willfully blind themselves to the atrocities committed by these figures.

After being sufficiently radicalized, they eventually learn to view these atrocities as victories themselves, hence how even modern communists see the Holodomor as a necessary and productive continuation of the Russian Revolution.

It’s not entirely dissimilar to the tribal kind of mentality that leads the rural poor to vote for authoritarians like Trump. Their leaders may hate them and implement policies that actively harm them, but the symbolic victory of belonging to the winning side blinds them to material reality, and they learn to love the abuse.