Historically, it's because it changed air travel. Airships were converted to using the non-combustible helium instead of hydrogen almost instantly.

But even that point aside, like the titanic, like the supposed war of the worlds riot, like the great fires of Chicago here and London over there, each great catastrophe gets one chance to completely knock us senseless. It's only by the subsequent ones that we start going "yeah, I knew that was possible. Wonder why they didn't prepare?"

Minor historical nitpick here, but the audio you're referring to was a radio broadcast. Moving pictures didn't have sound in those days; someone else just paired the two together later.