Well I never have had a single stripe... Hehe! I've always considered that the stripes are more to motivate people constatly. You know, some people need countinous encouragement, so this way they get a stripe ever 3-6 months and they have a clear goal that way.

At the places I've trained it's mostly been more or less so that you are a white belt until you have proven yourself worthy of the blue one. This is most easily done by competing and taking home a medal. But some people don't have to opportunity to compete so they will just have to prove that they can hang with the blue belts (harder to prove yourself that way if you ask me...). Achieving purple belt will be even harder to achieve without competing, but the same thing applies here aswell.

(Funny thing was that they were playing the white stripes on radio while i wrote this :) )