What happens when queer theory transforms facts (this man is not a woman and therefore can't be a lesbian) into value judgements (you are excluding this 'woman' for not fitting your ideal of womanhood)?
A thread.

Queer theory promotes the subversion of any social norm and sees any norm as intrinsically oppressive for the individual. By extension any socially ascribed value, any classification, any form of discrimination necessary to define and comprehend the world, is oppressive.

This ignores the fact that many norms are created for the common good, to protect the most vulnerable. How deeply suspicious of society, individualistic, and pessimistic such ideology reveals itself to be! It is also entirely decouped from (secular) morality and collectivism.

The classifications of the natural world are man-made, their emergence tied to different cultures and times in human history & rely on social conventions (such as words) which can be ideologically tainted. Therefore they are seen by the proponents of queer theory as oppressive.

But this ignores the fact that the natural world and the distinctions between its different components pre-exist humanity and society. While humans tended to ascribe a hierarchy (value judgement) to the existing differences, they did not invent these differences: they exist

naturally, neutrally, objectively, as a matter of fact and for reasons (survival, evolution, reproduction) we can deduce from scientific inquiry and that have nothing to do with human ideologies and political motivations.
There are objective distinctions between males & females.

There is nothing oppressive in the fact that human beings exist in these 2 different sexed forms, or in the fact that sometimes individuals don't fit neatly the most functional female/ male form.The oppression resides in the hierarchy that society attributes to these differences.

By all means, reject the social hierarchy of gender, but don't reject the reality of sex from which stems most life on earth just because you disagree with the social norms arbitrarily ascribed to your sex and find it easier to deny reality than transform society.

Queer interprets nature itself and natural processes as oppressive forces that can only be subverted by treating the natural world and its components as a shapeless mush with no other defining feature than the will/desire of the individual.

In such world, there is no possibility of consensus, and therefore knowledge. There is no possibility of creating a society with common values and a useful understanding of the world, of collectivism and collective liberation. There is only possibility for individual escape.

It is diametrically opposed to the values of the enlightenment and the empirical scientific method that brought us most of the medical, social and technological advances that we know today and that fuelled the dream of equality, freedom and social justice that we all hold dear.