Everyone is entitled to take risk in their lives, we knowingly and mostly without being aware of it at all measure & take risks everyday. Of course air shows / races should be as safe as possible...but it isn't possible to have no risk. As awful as it is those that race and spectate at races are taking risk but it is the excitement from that risk that makes us feel alive.
Any crash at a show inevitably brings comment about old 'planes and old pilots and a call to end such shows (making life just a bit more dull) yet the same outcry doesn't follow a road crash nor does the same outcry stop governments stop unpopular wars or such.
Just proving that humans exhibit some strange vagaries when it comes to risk & freedom of choice I guess.