Oldberon - "the comparison to annual road deaths is not valid".
Of course it is valid as it allows you assess risk and decide your actions.
From your example, if such an event happened you wouldnt venture onto said motorway until is was over. But would I go on that particular motorway the next day? YES, of course I would!!!!
I have to fly to accident sites, sometimes on a sister aircraft of the unfortunate aircraft that has come to grief. Do I hesitate? No. I think about it of course, but generally in life lightning does not strike twice... That's my assessment of the risk of getting on that sister aircraft.
Therefore not going to the theatre in London because of what happened at the Paris concert, or not getting on a plane because of Metrojet, is an over (albeit human) reaction.