Roosvelt Freeman wrote:
Probably they are talking based on their personal experience like "I have my black belt, but I still don't know Jack."
Possibly but more likely
a) they know how long it took them but understand it varies from style to style, dojo to dojo, person to person, how often they train and what sort of talent they have. There is no good answer.
b) they know about a) but are too wrapped up in its "not about the belt" to see that it does have some importance for those that are working for it. Its a self centered view but hopefully they will get past it.
In the dojo where I did my grades, a reasonably athletic person who trains 3-4 times a week will have Shodan within 4 years. Some get it faster, some longer. Let's say 3-5 years.
The black belt is usually presented as a gift from your teacher. Of course you pay for it through a higher test fee but with color changes within the kyu grades the belt cost is more explicit.