Nice to hear about the QL. Everything you said about it is true; However when you said that walking is good, I'd say it depends.
Imho, 99.99% of the people don't know how to walk--even worse about running. Our fashionable clogs are the main reason. The other one is laziness.
Heel striking, thick soft soles and foot movement restriction are the flaws. The correct way to walk is barefoot. We evolved with that faculty. The way we use our feet has consequences on how we stand, move and think. Tensigrity from our bones, muscles and fascias propagate up to the top of our skulls.
When we make use of our feet properly, it implies that we move our lower bodies--feet, legs, butt and hips--in order to balance our upper bodies in equilibrium without improper tensions. On the opposite, heel striking makes our backs tense and rigid. Thus the always contracted QL, inter alia.
If people would know how to walk and run properly--with minimalist shoes for safety, cleanliness and social conventions--they would use all the muscles in their feet, legs, butt, low back and hip properly. The QL would be active, thus back pain would vanish.
