In their current state, belts and competitions are nonsense. (Or why I'm never eager to compete …)
Quite simply, belts are not a guarantee of mat time, and we know mat time (MT) is the most important measure of skill, followed closely by the quality of the training partners as well as the actual training method (mixture of rolling time, drill time, technique time, calisthenics time).
If you don't buy this, as a thought experiment, just take a moment and imagine a blue belt and his twin brother who both train at the same gym, but one of them trains three times as much as the other. They get promoted following a set schedule, so as to remove any instructor bias, but I bet you'l be able to tell them apart if you saw them rolling against one another. This is where belts fail us.
Let's then agree on a number of hours a hobbyist typically trains per week. Does something between 2-6 hours a week seem fair ? That's your hobbyist . If now you get someone training 7-20 hours a week, there's your semi-pro. That is, he might beat the pros sometime, but the odds are against him. Then you have the full time typically unpaid pro, who puts in 20+ hours a week. Now if you think a hobbyist has a chance at beating a pro in competition (we're talking cumulative mat hours here), I have a name for that : it's wishful thinking. This is where competitions fail us as a measure of "who is better".
Therefore let's put athletes in two buckets. Let them declare for themselves that they're either :
an amateur - hobbyist - professional - family dad - I can train no more than let's say 6 (ish) hours a week
I train at least 3-10 TIMES more than the hobbyist . I need money to support myself and aspire to become a world champ.
Create an amateur-only division, but allow them to join the pro divisions. Is this unreasonable to ask ?