Big balls have been a prerequisite for top riders since Hildebrand met Wolfmuller.
Kenny Roberts started the safety consciousness that caused the GP to leave IOM. There are more deaths there yearly and have been for many years than MotoGP experiences in a decade. Brains in the skillset toolbox to go along with those big balls prevent the retirement-by-death plan so many top real road racers experience. Going fast is never going to be completely safe, but approaching 200 mph on public roads, even closed ones, is insanity to the nth power. Limiting them to 150 or 130-mph machines would only make it incrementally safer, especially with those old 130 mph brakes and suspension.