I think most of the non-inclusiveness comes from just lack of experience and fear. Fear of all sorts, but basically fear of unfamiliar. Difference is just anxiety provoking and it is innate. And all we are just experiencing this uncanny feeling when we confront with an unfamiliarity. Many research also support this hypothesis, including the well known harvard implicit racism test that can be found here: https://implicit.harvard.edu/implicit/ , which reflects that racism (and other non-inclusive attitudes) are strongly correlated with unfamiliarity and fear.
Freud describes the fear of unfamiliar with the term “unheimlich” that can be translated as uncanny, and Lacan sets the uncanniness, the anxiety at the core of human existence. As does the various philosophers including Heidegger, Husserl, and Sartre. So, I think, before heating the discussions with divisions, we need to sit and listen the other being (whether s/he is inclusive or not, or familiar to us or not). Since we are all humans, eventually the familiarity will reveal itself, that will soothe the anxiety.
In this regard, I do think that the strongest tool to promote inclusiveness as a mean to reach the best versions of ourselves and help people do/be their best is to work on the principle of familiarity. Neurologically speaking, without including limbic system (aka emotions), and just focusing the prefrontal cortex (aka thoughts), we can not create effective learning. Learning happens when the brain is involved in the process as a whole. Thus, rather than setting signages for human zoos, we can invite and welcome the personal stories and highlight the similarities, rather than getting lost in the rabbit holes of differences. Here is an amazingly wonderful speech by Chimamanda Ngozi, named The Danger of Single Story, showing how the prefrontal cortex focused training induced educated-blindness effects the relationships and providing some delicate insights on how similar we humans actually are, enjoy if you did not before.