Well yes, she wasn't properly equipped for a three night stay. She also should have had a VE-25 tent, 0 degree rated down bag,and at least one stove, plus meals. That way she could have served hot tea to her rescuers. She had what she had, and it kept her alive. Survival is ultimately graded as pass/fail. She passed.

I agree with your point that a plastic bag isn't perfect. On the other hand, it is cheap, handy, and light - easy to tuck away until needed. It has its proper place and it can be useful.