The reason those sell is because of the price.
A GOOD kit like that, with quality components would cost at least 4x as much. I've seen some backpack based kits using good components, and even "survival guys" balked at the price. You'd be surprised at how much even a rudimentary kit with good components cost. People just don't realize it because they buy a piece at a time.
Just take a look at your kits, and add up the current prices of the components, include shipping, and you'll most likely be over $200 for even a modest kit.