Roll hoops didn't seem so obvious in the days before belts, bagtanks and Nomex - many drivers counted on being thrown out of the car rather than staying in an inverted, burning car. Still, with hindsight, it really does seem rather odd how little considertion was actually paid to safety in both road and racing cars for many, many decades.
Many US racing cars did have seat belts (of sorts, usually just a lap belt, ocassionally with shoulder straps as well) and roll hoops in the 1950's, but the hoops were seldom braced adequately in the longitudinal direction.
