“However the Border Patrol disagrees. The men and women who are actually charged with doing the job specifically requested a system they can see through.”
The bollard type fence-wall is also easier to repair if cartels or others damage it. A concrete structure could take weeks to repair if damaged in a remote area. It takes more specialized skills to construct, maintain and repair. The bollards are a much more cost-effective system.
Indeed. All good points. But, from interviews with the Border Patrols point of view, they wanted a barrier system that they could see through so they could see what is going on on the other side of the barrier.
Your points, all valid, simply add to the logic of the final design selection.