feels:
How is fighting bare-knuckle strange? Even though we don't allow hand strikes to the head, there are plenty of strategies for downing an opponent. Rounds are usually too short to "wear down" an opponent and are fought at a much faster pace than any other combat sport. The objective for the fighter is produce one solid strike that's capable of putting the opponent down whether it's a uppercut to the liver or a kick/knee to the head. Sure, we exchange a lot of shots that don't connect as intended, but it's not a race to see who gets knocked out first like how Gary Goodridge fights.
It is also rare for world-class Kyokushin fighters to break their hands. Wrist and hand strengthening is basic procedure during training. And many Kyokushin dojos always stress the importance of keeping the hands and wrists strong in order to prevent injury. A broken hand or wrist may happen occassionally, but what combat sport doesn't produce injured fighters?
I'll admit, kumite is fought a strange distance compared to other combat sports; thus, many fighters have a difficult time adjusting in order to fight up close. Stand-up fighting, in general, isn't the most realistic in terms of combat either, whether it's Muay Thai or Kickboxing. All those sports have rules, too. It's only a matter of how well a fighter handles himself within the limitations of those rules. People can say that most Kyokushin fighters lack head punching defense, which is true. But I can tell you that a Muay Thai fighter or Kickboxer would be a fish out of water fighting under Kyokushin or WTF rules.