wanna race, gotta take some risks
We all take risks driving our cars on public roads. I think you're safer on a track as long as you don't want to win and your car is properly maintained per modern race car procedures (yearly full teardown and crack check, don't reuse 40 year old suspension arms, etc.). If you want to win, by definition you'll be driving closer to the limit than you should on public roads, and thus stuff like this happens.
It's hard to imagine crash damage that's too severe to repair, as long as cost isn't a big constraint. Think of how many cobra's and other vintage race cars have been resurrected from just a one small bit of scrap metal containing the chassis number. We're lucky that E9's are plentiful enough that donor's can easily be found for restoring horribly damaged racers.
John