We all realise there is an element of risk in aerobatic flying and this type of air display, as with many other entertainments.
If you buy a ticket to attend, or maybe don’t buy a ticket but choose to view from a public place or even to view by stopping (trespassing) on a public footpath, then you accept that risk.
However, in this case it appears that most who sadly lost their lives were simply going about their lawful business.