And hitting the terminal would likely have resulted in far more loss of life. Are airport designers supposed to consider this as "an eventual certainty"?
Yes, but there is no terminal at the end of this runway, so it’s irrelevant. The question is, wouldn’t it be safer to design airports to avoid having large concrete structures at the end of a runway in case there is a landing problem.
Terminals are generally located to the side of a runway at some distance, where a plane aligned with the runway is unlikely to hit them no matter how fast it's going.
Not sure if there's a regulation that requires this kind of arrangement, but I wouldn't be surprised if there are stricter rules about structures that cross a plane's usual trajectory.