The best gear in the world, poorly used, is often not as efficient a mediocre gear used well. I've used mylar sheets a number of times. As a personal shelter (ie you are wrapped up in one), the mylar sheets are mediocre. You can do better. But they are better as a shelter building component than the "superior" counterparts, due to the increased reflection of heat and light. Properly used, almost everything has a value.

By having your fit about these mylar sheets, you are also confusing a retailer, Redflare, with the designer, Doug, of an item produced by a manufacturer, Adventure Medical, which is internationally recognized as one of the best in it's industry. Neither that designer nor that manufacturer have anything to do with mylar sheet blankets, other than to say "they do work, sorta, and you can do better". Redflare has mylar sheets, and Heatsheets, and other products. You have compared apples, oranges, and grocery stores- I'm not sure I see the point you are trying to make.

But the one thing I'm not sure you are quite getting is this- the sale of those products, among other things, helps keep this forum running. That takes money. This forum is another one of those Doug Ritter products that (and I apologize in advance if I'm misunderstanding) you seem to be saying are a kind of sell out.

If you don't like the product, don't spend the money.