[quote/] I agree. But from a "trek science" point of view, I think the logic is that the Borg don't want to "waste" resources to assimilate someone when there is no imminent need. If they have a full crew, they won't bother spending the time to assimilate (including outfitting the new borg with the electronic appendages).
Though logic would say that after BOBW, the Borg aught to have known that humans on board leads to bad outcomes, and they should have attacked on sight.[/quote]
Yea I think they only assimilate if that is the task at hand. But in first contact the task was to stop first contact. I think they will also only assimilate if they think they can gain something fromt he species either intellecutally/technologically or Biologically.