Two factors have not been mentioned here, that probably are involved in the cause of the unfortunate events of this cruise.
First, a year or so ago RCCL lowered its drinking age to 18. Not only can 18 year olds drink all they can afford, but this makes the "fake ID" presented by a 15 year old more believable.
Second, it is a poorly kept secret that all of the major lines have been reducing crew numbers recently. Thus, a lack of supervision and security.
Finally, I don't think Kuki meant his comments as racist. After all, to my observation, most of the people of Puerto Rico ARE white (whatever that means), and they ARE US Citizens. What I think he means instead is that the last minute, "give away" prices some lines give AFTER the time to buy affordable airfare has passed tend to attract a "rougher crowd" from driving distance to the port ---- wherever the port may be ---- due solely to the low price. There have been reported problems like this from cruises sailing out of Florida as well.