Here's the most important thing to remember about accredited black belts: There is no such thing as an accredited black belt. It's not a college degree; it's a piece of clothing awarded to you by your teacher according to his own subjective criteria, which could be anything from hard work and crazy skills to having a lot of money. Hey, did we mention that any random dude off the street can become a martial arts instructor?
"My qualifications include owning this suit and Googling 'martial arts poses.'"
And as it turns out, the belt color system ranks among such other "ancient" wonders as driving and flying; it was invented barely a century ago. The first belt system was devised at the turn of the 20th century and was implemented for students of judo -- a style famous for literally not allowing the kicking of asses. Ever since, the black belt has served as an effective means of both showing off and making instructors' wages.
But it still means you can kick ass, doesn't it? It's not like any kid can get a black belt just for showing up and paying monthly fees, right? Wrong. Many schools now advertise black belts in a guaranteed time. You pay, then a year or two later you walk out with a black belt, regardless of how often or how well you trained. This happens so frequently that the martial arts community has come to call the schools "McDojos." Ask nicely and they'll tell you all about their birthday party packages while you're there.
"Free toy with every yellow belt!"