The more shock absorption the shoes have, the harder the feet will fall on the concrete, due to perceived softness of the ground. This is particularly true of a lazy runner who runs with no real control, and will plod along in complete non-awareness of their body. If running on concrete barefoot, the feet will fall very softly, and naturally adapt to a proper running form, because to do otherwise would hurt like hell. The more advanced the shock absorption of a shoe, the more likely it is to exacerbate twisted, unnatural running habits. If someone is already prone to running injuries, running badly, putting more insulation between the feet and the ground will actually make things worse. It is better not to run at all in this case.
Also, running with shock absorbing shoes makes the feet lazy. Try walking barefoot for a long time, especially on rough/grassy hilly terrain, or running. Even if you're used to running or walking long distances in your ultra-air cushioned running shoes, you will find your feet ache relatively quickly. This is because you're working your feet muscles for the first time. They become weak using these so called running shoes.
Running barefoot or with minimalistic cushioning is a lot like fasting and eating less. People think it is dangerous and will hurt you, when in fact it is just the opposite. Proof that they are dangerous is often cited from immediate symptomatic effects, like tired feet, or the feeling of a bit of pain walking over rough areas for the first time barefoot, or having to, horror of horrors, actually learn to run all over again and be careful as opposed to smashing down without regard for what is underfoot.