I think what he's saying is that true, lasting happiness comes from "unselfish sacrifice and compromise" to one another, instead of from from finding a "match somewhere that is maximally mutually compatible".

That is how I see it too, and in fact it seems to be how the writer sees it:

  > The person who is best suited to us
  > is not the person who shares our every
  > taste (he or she doesn’t exist), but
  > the person who can negotiate differences
  > in taste intelligently — the person
  > who is good at disagreement. Rather 
  > than some notional idea of perfect 
  > complementarity, it is the capacity
  > to tolerate differences with 
  > generosity that is the true marker
  > of the “not overly wrong” person.