Unless you mostly use it like I do, with the ignition off and the spark plugs out to rotate the engine to TDC so I can set the point timing.
The few times I've actually started the car using the crank, I have been careful to have my thumb on the same side of the handle as my fingers and to only do a pull on the handle, never a push.
Given how rarely my Plymouth L-6 has back fired on starting, I guess you could get away with doing it wrong for years without injury. Now a 4 banger with a manual spark lever set in the wrong position is a whole different animal...