I'm not being negative about someone CHOOSING to use additional safety gear. The question was about changing the rules to require full roll cages or additional side impact bars.
There's are big distinction between requiring a full cage car (ie an SCCA race machine) and our current AROSC race group cars.
If someone wants to run a full cage, fine. If they don't, that okay. And from a safety stand point, if you look at the history of racing events that allow race cars with only roll bars (eg vintage racing), I have not heard of any racing fatalities or even serious injuries from racing accidents.
I have heard of lots of racing fatalities in race cars equipped with full cages and equivalent safety gear.
Looking at the data from racing events is far better than theoretical musings, since data is reality. The difference, of course, between events that require only roll bars (sports car clubs like AROSC and vintage events) and all out competitive racing is in the attitude of the competitors. In the Alfa Club and vintage events, contact and aggressive driving is not allowed. That is not the case even at a Buttonwillow regional.
I once watched the start of an IT regional at Buttonwillow and by the time they got to the hairpin, the cars were 4 wide. Virtually every car was off the track and every car made contact with someone. And the stupid thing was, after they got all sorted out, there was almost no passing--in other words, there was no need for the Banzai charge into the hairpin at the beginning of the race since the drivers and cars finished just as they qualified.
That convinced me that I would NEVER go SCCA racing. In fact, I have no desire to race at all. Racing the clock is just fine with me. My day job is plenty stressful enough.