it's a combination of wladimir being really good and his competition being really mediocre. but you can't blame the klitschko's for their bad competition. as long as they keep winning, there is nothing they can do about their lack of top caliber opponents.

however, if they were fighting in the 1970's, they would still be good but not as dominant. with muhammad ali, joe frazier, ken norton, ernie shavers, jerry quarry, george foreman, jimmy young, larry holmes and others, it would have been very difficult for the klit brothers to dominate. although because of their physical superiority, they might have won a world title at some point.