The point isn't the number of people dying. Its the chilling effect. Travel was way down after 9/11 due to fear. That has a much bigger economic effect than just the deaths.
In the 1970s there was no airport security. Airliners believed it would be cheaper to just pay off plane hijackers. That was before those hijackers started flying them into skyscrapers.
The lower airline travel isn't just from fear; it's also from the additional time and hassles of security.
. . . although after many years of not flying, in the past 2 months I've gone through security about 10 times and it's always been pleasant and professional and quick.
In the 1970s there was no airport security. Airliners believed it would be cheaper to just pay off plane hijackers. That was before those hijackers started flying them into skyscrapers.