What do I think the explanation is for her quitting right before the finals? I obviously don't know for sure, but I strongly suspect that she was afraid of underperforming. Problem is ... her quitting doesn't affect just her ... she is part of an overall team. You don't flake out and walk out on your team after taking it all the way to the finals. You give it your best and let the chips fall where they may. It's a competition, not life and death. Apparently, her psyche is too feeble to know the difference ... and that quitting reflects FAR worse on her than competing and falling short of her goal.
The essential American soul is hard, isolate, stoic, and a killer. It has never yet melted. ~ D.H. Lawrence