@Axiom
I emphasize with your frustration. In your shoes I'd be pretty aggravated. But here's the thing...
It doesn't matter what belt anyone else is wearing and what they did and didn't do to wear it. A woman/girl (I can't remember, but I think it was a female) passed a grading even though she didn't break the required boards. Others haven't completed their forms, botched them, etc.; others just show up once in a while and test and pass. So what? What's that got to do with you and just as importantly your abilities? How does anyone else's work ethic make any difference in your progress? I talked about a guy at my dojo who's been a 3rd kyu for about 7 years because he's inconsistent in his training. If he was in your dojang and reached 4th dan with his lack of dedication, what exactly does that change in YOUR training?
Sure, it'll give you a feeling that everyone else's belt is worthless and yours is by association, but what else? Do you want the belt so you can wave it around to your friends and family who don't know any better? Do you want the satisfaction of saying "I'm a black belt" out loud?
I was promoted to 1st dan in 1999. I thought it would be this magical and mystical thing that would transform me into some super karateka. Ok, I exaggerated a little, but you get where I'm going. Half way through my first black belts only class it became painfully obvious (figuratively and literally) that I had this belt on a pedestal. I was still just JR. I was pretty good and worked my butt off to earn it. The belt was pretty far from being an attendance award in every way.
What's my point? Me wearing it didn't make me better nor worse. And the guys and ladies standing on either side of me didn't make my belt better nor worse either. I stopped chasing rank. I stopped caring about what I wore around my waist. I realized that my belt had nothing to do with what I knew and could and couldn't do. I stopped caring about my belt and everyone else's belt, and put all that energy into just getting better.
I left karate for almost 15 years, and restarted 2 and a half years ago. I started at white belt. I tested for every rank so far. If all goes well, I SHOULD (
) be up for promotion around December/January. I look forward to the test, but I really don't care about the new belt. All it'll say is I passed. It won't make me better. If I'm the lowest rank or the highest, it won't matter one bit. It'll tell my teachers where I am in the curriculum and it'll help keep my gi closed. And it's not that effective at with or those, because I know most of the 1st dan syllabus anyway.
But here's the interesting thing - I'm far better as now as a 3rd kyu than I ever was as a 1st dan. And I'm 20 years older. The old black belt means as much as my current advanced green belt, and as much as the brown belt I'll get when I eventually pass that test.
Forget about your and everyone else's rank. Chase improvement. If you fixate on that, you'll do great. Fixate on anyone else, and you'll just waste too much energy that could've been used elsewhere.
Sorry for the long story and pep talk.