Failure in an engineered system is rarely a binary condition, though the FSC bridge is a type that fails catastrophically once you fully remove that pillar. But, recognize that you can damage the pillar without removing it.

Anyway, the protection system necessary for the bridge isn't just a factor of the design of the bridge. Like I referenced in the previous comment, it's dependent on the traffic going under. The world's biggest bridge would never need a collision protection system if the boats going under were small enough.

This isn't a hindsight problem. Bridges have known traffic under them and should be rated to withstand impacts. It's extremely easy to predict what the largest possible impact is for a particular bridge and plan accordingly. Do you think this boat was lost? This particular boat probably passed under that bridge a hundred or more times before it malfunctioned and hit it.