Well . . . in support of the locals . . . . they get tired of people coming down and doing stupid stuff. Frankly, this attitude is also mirrored overseas because it is the "ugly American" who makes a spectacle of himself/herself. No matter where you go, people appreciate you much more when you try to learn something about the local environment and customs.
In this case, the divers violated Florida law of swimming without a float, and violated good diving practices as executed in the keys. Furthermore, the Coast Guard and others that participated were locals . . . how many times do you have to bail someone out for being stupid before you get fed up? (Think about raising teenagers . . . )
All in all, they were lucky. However, good planning and diving practices would avoid the need for luck, one would think.