You didn’t attach the poem, but I would assume that it is because the boot is used more frequently, and there’s a familiarity between the boot and a person that isn’t always present with the dress shoe– one is likely to be owned by many.
I think the cultural differences between the colonizers and the countries that they have colonized. I think language describes both divisions differently. In the sense that the colonizers were called man while the natives were being referred to as savages. Their cultural barrier make language more powerful in that sense the labels given to colonizers were better compared to the savages.