Outside Magazine possible survival mistake? 5-2014

We all like neat good tips.  But a solar still to survive from a half  a plastic 3 to 5 inch water bottle?

Solar stills of large size of 6 feet across with lots of plants or bad water only yields about a cup a day according to those who have done often in testing including Master Chef Sgt., Survival instructor 12 yrs at  USAF, Peter Kummerfeldt.

Neat idea but too little water for the effort and that's with a 3 to 6 foot
diameter plastic tarp not a 3 to 5 inch water bottle !

Several respected book sources follow.

Surviving a Wilderness Emergency by P Kummerfldt
full of good ideas that WORK but does not give space to "solar still"

Colorado Division of Wild Life Art of Survival "a 3' diameter solar still does not produce enough to keep you alive"

Outdoor survival Guide by human kinetics - The stil should be 3' to 5 ' in diameter and may take more water to build than it will produce".

ARMY FN 21-76 has many pages on obtaining and using water but solar still is not in it 300 pages
 

Essentials of sea Survival Golden/Tipton "the theoretical concept of the solar still [6' diameter suggested]is excellent but the practical performance is extremely poor"  [NOTE not just poor but EXTREMELY POOR and this is 6" not 3 inches]
This is possibly the greatest, newest book on sea survival

US Air Force Survival Handbook "due to the low yields obtained from of this device---solar still will not equal body fluids loss during construction and even hasten dehydration".

IF 3 to 6 feet diameter tarped sealed hole wont keep you alive why waste time on a tiny collection 3-5" bottle  which with out an enclosed space cant even work ???