amazing how the car industry wouldn't put up with anything that is so intolerant to mistakes and can be crashed so easily. He would have been sued (and lost) long ago
That's not entirely fair. It's a bit like giving driving schools fast sports cars that are really hard to control, and after pupils keep crashing them, saying "these cars are unsafe!".
Frank designed the R22 as a personal transport aircraft. NOT as a trainer. Schools adopted it because of cost reasons.
The R22 is entirely safe as a trainer.
IF you know how to teach in it properly.