When does Unaccompanied Baggage Become a Security Risk?

I am confused! Apparently one reason we were not able to take an earlier flight to Madrid and so catch our connection to Santiago was because our baggage had to fly on the same plane as us.

OK, so that is understandable, after all it could be considered a security risk and no one should take any chances when it comes to the safety of airliners and the passengers and crew who fly in them?  But we were told that unless the bags could be unloaded from our delayed flight, we could not fly on an earlier flight.

Then it turned out our baggage had not in fact been loaded on the flight we did eventually take and so we would have to wait in Madrid for it to arrive on a later flight!

So please tell me, how can it be unsafe for me to fly without my baggage but perfectly safe for my baggage to fly without me?
Categorised as Road & Rail