Was at Fairford a week ago - probably like any airshow, you can't eliminate the risk without moving the spectators a mile or thre from the runway.
Even though none of the aircraft flew over us, it wouldn't have taken much of a "glitch" at 500 knots for the aircraft to deviate enough to be over the crowds.
Sad when this sort of accident happens, but I'd rather take that small risk than be so far away that I need binoculars!
Gotta take some chances - or stop riding in busses! (no pro-Boeing pun intended there)