Doesn't it perhaps say that the Borg are less seductive in their claims to be agents in the search for perfection then what they actually are?
Humanity (or Klingonity or Vulcanity..) is real. The Borg are just sock puppets. They don't know it, but unplug a person and their real species rears its beautiful head.
(This is my in universe explanation, I agree with you about Star Trek and the Holy Altar of Human-ness)