I don't know where you're from but over here, children make up the vast majority of people who take up martial arts. In most cases you get a child whose maybe 8, 9, 10 who wants to try it out so they do it for a year, get their green belt, hang it up on the wall, show it to their friends, and then move on to other stuff. Children by far make up most of the business. If you've ever been to a MA tournament over here you will see they are mobbed with children who are 12 and younger. Teens and adults make up a smaller portion of tournament participants.
As to why Im linking the two and why it matters is because of this, asking about rank, and there I go about rank again, there is nothing wrong with asking your scoutmaster about rank in boyscouts. Although the handbook spells it out about what you need to do for each rank there are still some things which might be unclear to the scout and there is nothing wrong with asking the scoutmaster about it. Asking your sensei about rank in the martial arts, on the other hand, is often seen as disrespectful and can sometimes even get a student a six month suspension in rank advancement as this other member of the boards posted on how he does it at his place. Anyway in both MA and BS, I am talking about earning rank, not buying it or having it handed out. Anyway, what Im getting at is whats the difference in asking about such stuff in scouts vs martial arts aside from, "martial arts isn't boyscouts."