nicknames ADD to the fun of MMA.
In other sports you have to reach some level of greatness to get a nickname.
for example in baseball; Babe Ruth: the Bambino, the sultan of swat. William "the fridge" Perry in football. These names are to outline and exemplify the uniqueness and aura of a special athlete.
In lots of traditional sports the best players will play the sport "perfect" but it will look the same as other players. They are limited in self expression to perform to the limitations of the rules of the sport.
In MMA there is a lot more room for expression, as each fighter can have a unique style (or combination of styles)... Of course there are cookie cutters and fighters who emulate each other but the variety in our sport is second to none. When someone gets a name that encapsulates their style, it adds to the thrill of calling the fight, talking about the fighter himself and just his overall image and mystique.