“One-sided dichotomy” is a term I would like to coin to describe a common situation in public discourse.
My first example is the distinction between second-wave feminism and third-wave feminism. Ostensibly, second-wave feminism describes a movement circa the 1970s, and third-wave feminism describes a movement circa the 2010s. But it should be obvious that feminists in the 1970s did not at the time make any such distinction. Thiss is a dichotomy between two groups, but the dichotomy is only made by one of the two groups. Thus, a one-sided dichotomy.
One-sided dichotomies have a tendency to be unfair, because it is only one side controlling the narrative. The narrative goes that second-wave feminists were primarily focused on equality for wealthy white women, while third-wave feminism is intersectional. But closer examination should show that at least some feminisms of the 70s were intersectional, and some feminisms of the present day fail to be so. Does that mean the dichotomy is unfair, or am I nitpicking? You decide.
I must emphasize that one-sided dichotomies are not necessarily unfair. A model example is the gay/straight dichotomy, which certainly started out one-sided. Straight people would have rejected the label (“I’m not straight, I’m just normal”) or simply wouldn’t have given it any thought. Now the dichotomy is broadly accepted. Another dichotomy currently following the same trajectory, is the cis/trans dichotomy.