Either that or certain poly families/communities
have it written in their beliefs systems that understanding you are not special or unique and do not deserve any other family or community affirmed notions other than each individual is average, mediocre, nothing to write home about at best.
However there is nothing wrong with believing your are unique, special, or that someone would desire your company over others so long as you treat others with love, honesty, and a mutual respect because for the same reason that each individual is special and chosen over another, for the same reason one person prefers you, another person prefers to not chose to be around you.
For some reason their are groups that seem to practice a lowest common denominator type view of the self, instead of celebrating uniqueness and understanding that it is OK to desire to be important to others. But to also realize how damaging it is to attempt to make others feel less important and call that love.
some groups that require conformity place value on or consider it necessary to break a person's spirit so that they fit into a group, when all that ultimately does is not allow more freedom, but effectively give another more control