The citation you give is correct, albeit a bit misleading.
If a rocket fails so soon after launch that it strikes any of the structure on and around the launch pad, the result is in any case a huge explosion resulting in the complete loss of the vehicle. You can get an impression on how it looks like by the crash tests done by SpaceX in the past years using almost empty rocket booster stages (just with 100 times more fuel in the tanks). In such an event it is clear that all the buildings will suffer severe damage and a few concrete pillars will not make much of a difference.
Second, given the small size of the array, it is very unlikely that the rocket actually hits that. This makes it clear, that this wasn't built to save the rocket or the surroundings.
The only case the pillars make a difference is for the building underneath them - the control bunker of the launch site. In the unlikely case the rocket fails and significant parts of it drop on top of the bunker, there is the risk of damaging the concrete ceiling. The bunker seems to be quite robust, located 60 steps below ground - but on the other hand, 500 tons of of kerosene and LOX is nothing you want to have exploding just on the other side of the wall.
If the rocket hits the ground and explodes, a significant amount of energy and force is directed downwards because of all the additional material dropping down from above. This force can reduced substantially, if the rocket explodes while still airborne: The shockwave can extend in all directions, debris can spread and the "crushing" effect is not as strong as the lower parts of the rocket still can move further down.
This is exactly the purpose of the pillars: Breaking the rocket apart before it hits the ground and the top of the bunker.
Side fact: Tanks (the military things) use a similar technique called "reactive armor" - the tanks are covered by an explosive material that repels incoming projectiles and reduce the forces and destruction despite causing an additional explosion.