I have an open mind when it comes to humor. In fact, I am borderline overly immature.
That being said, I find this type of humor to be sickening. Many of our young Marines (and other members of the armed forces) have been crippled and can no longer pursue their dreams (e.g., fighting or sports). It's no laughing matter.
Good thing they aren't making fun of crippled marines then right? The joke was about someone with metal hands trying to fight in the UFC and you are just twisting it to be about something else.
Current issues are the number one source for comedy and you can't expect people to sensor themselves because it may offend someone.
Either everything is okay to make fun of or nothing is. There is no grey area in censorship.