I hear ‘primary’ and think ‘favorite’, which I find somewhat hurtful. My partner and I try hard not to use these terms, yet find it tough because the fact of the matter is that, with his other relationship, there are various entanglements. I believe I would thrive best in familial poly situation, no question, but for now I try to work on not concerning myself with labels like these that have a negative meaning for me personally.
As far as others go, I don’t judge them based on what they do or don’t label their partners.