All of which would be a fine and dandy argument if display accidents ran at one every 20 years. Sadly not the case.
The point was being made with regard to accidents causing the death of spectators at the air show or those going about their business outside the airfield boundaries - as was the case at Shoreham. The mitigations put in place wrt crowdlines, not flying over or towards the crowd etc have successfully ensured that spectators and others are not put at risk, going all the way back to Derry's accident at Farnborough, significantly more than 20 years.
The unfortunate kneejerk response to display requirements taking much of the flying further away from the crowd and thus outside the boundaries provides even further protection to the crowds, who don't really need it, and increased risk to those outside the airfield, who in some cases are now closer to the aircraft than the paying spectators.