IMO, it is up to the faster driver to make a clean pass on lapped traffic during qualifying or the mains. If the lapped traffic blocking excessively, then the race director should intervene. Usually the lapping car is faster for a reason (better car/better driver), so there is no excuse for punting anyone. I've raced with fast drivers who have no regard for slower traffic (punting on the track, yelling on the stand) and ultimately they drive away racers. Good for them since there is fewer cars they have to pass, bad for the track. I am always surprised that a lot of fast local drivers don't have any idea how to race in traffic.
A good race announcer will prevent blocking/punting because they will let everyone know where they are on the track and who they are racing. Most (not all racers) will show faster racer's respect and let them by.