This is a statement on same sex 'marriage' from an organization calling itself a 'church', a Christian church in fact:
I can't see any reference anywhere here to religious morality, specifically not to any Christian reasons for opposing same sex 'marriage', such as Scripture or Tradition.
Lacking any such reference, this is just a set of debating points, more or less convincing, but in no sense compelling.
I suppose any reference to Scripture or Tradition would set a dangerous precedent: if Scripture and Tradition was referenced on this issue, then people might get the idea that the organization ought to be constrained by them in other matters - such as priestesses.
What was actually required is something very simple and clear along the lines that Scripture and Tradition forbid this, so we won't do it.
But presumably, something so simple and obvious and effective is what is meant by 'knee jerk resistance to change'.