It very much is, actually. First, it doesn't require a hypothetical vacuum: it could be a preference born entirely of our genetics, our epigenetics, or of epidemiological factors. Alternatively, it could be a social construct.
The reason why this is important: because we cannot meaningfully change genetic or epigenetic variables, and we are only beginning to have the ability to affect epidemiological vectors. They are outside our control in the most meaningful sense. As an example, homosexuality (and heterosexuality) are considered genetic and epigenetic variables, and as such are not considered meaningfully alterable even if our society was radically different. We can't prevent heterosexuality/homosexuality even if we wanted to.
By contrast, we can affect behaviors which are engendered by social constructs. Social constructs are within our control. This is precisely how women gradually entered the work force; our society changed in such ways which made women in the work force socially permissible, and over time (as in, nearly a century) the preferences of women changed.
