i guess police sketches are bullstuff because they're not 100% accurate too
your physical appearance is concrete and distinct. it's entirely possible for a sketch of a real human being to be objectively inaccurate. something as complex and abstract as ideology is a lot harder to pin down, and judging ourselves in relation to sets of two labels that we've arbitrarily decided are directly opposed to one another can only be so good at describing someone's specific ideology
ofc some tests can be better at determining these things than others and there's nothin wrong with criticizing them for their weaknesses, cus they're definitely sensitive to precise wordings and question choices