to support an argument that they are somehow obliged to be more supportive of BYU sports.  Or that they don't "realize" things - another common tactic.

AFAIK, President McKay never said that over the pulpit.  You are correct, it's from 1965, when a member of the Seventy attributed it to President McKay in GC.  I also believe that President Hinckley made a similar statement in the 90's in a television interview to give a short answer.

But again, my point is that it is much simpler and much more ineloquent than the actual mission statement of the church.  And yes, I may be splitting hairs here a bit, but my point stands that this kind of stuff is rampant on CB.  Misquotes, misattributions, and context shifts for the purpose of supporting BYU football.