If one is carrying it 50 yards, it may not make a big difference. It is only after carrying stuff for extended trips that it really starts being uncomfortable.

One issue is they appear to have designed an ultra-compact foldable bag for those times when the bike isn't stuffed in it.

It would be easy enough to design a bag with either padding, or a molded back that might even be designed for optimum weight distribution. However, the bag would loose compactness.