I personally have been in the circuit when a Yak did a R & B and it did not cause me any problems. I think on a day with good vis and not much traffic it can be done safely, and I imagine it is good fun to fly.
The North Weald accident was in unlimited vis with a single aircraft in the circuit.
What seems strange to me is that no greater responsibility for this is placed on the pilot of the Yak than on that of the pilot of the Cessna.
Yes! And what also seemed crucial is that the Yak pilot ASSUMED that everybody knew what he was doing.