really. i feel sorry for the dude. he lives in a society where everyone pretends that blood color does not matter, but it does. he is not at the bottom of his society's pyramid either. he is entirely off of it.
consider what culling meant on beforus. it meant coddling and pampering and spoiling. it meant degradation and condescension in its original sense. remember what kankri said to latula, about how her being culled due to her disability would have been contradictory to her "r4d1c4l" lifestyle.
whether or not kankri was culled, he lived in a world where any sort of difference was seen as a failing and where no matter who he was, he would always be an object of sympathy and pity.
so he decides to fight all of that. he learns the jargon, develops speeches, and stands on the defensive, ready to intimidate anyone who would treat him as a lesser. anyone who would suspect that he is not worthy of respect.
kankri is always fighting to stay afloat, to make his difference seem like a strength, when this fight is his greatest weakness. it makes him scared, weak, selfish, unkind, and, well, insufferable. because he is so used to seeing every opinion about him as being the result of his blood, he thinks that others' rejection of his arrogant, repetitive trope is a sign that they have not heard enough of it to appreciate him.
this could also explain his unwillingness to take on the issues of others. he is so cruel to mituna probably in order to avoid being associated with him, despite a few similarities in their situations. he rejects porrim's feminist philosophy because he has built his whole identity on being a victim.
kankri is fucking pathetic.