Thats what people did and still do.., damage will go both ways so no point on infliting damage, if people do it to ruin others race they will be penalised aswell.., its not random.
I know how it is cause i raced in private leagues with permanent damage.., wich mean a "small" touch and your race its ruined, with permanent damage people needs to box to repair...
It can sounds frustating but it is how racing works in RL..., and if permanent damage was applied to A+ lobbies probably only top splits could have that on since lower splits have A rated drivers also.
That will never happen but if did.., was good also for some top drivers that dont respect slower drivers, dive bombs and forcing others might cost them the race.
Its all good things, if you take the risk you must be ready to pay the consequences..., wich can be good if you respect your and others space.., if not race over.
Eventually people have to be more carefull, learning the danger of first corners and firt laps and so on.