It took me ten years from white to black, it suited me to take my time because I had a full time job working 12hr shifts two school age children, a home to look after and a husband who went on regular deployments. I learnt a lot, not just techniques but how to compete as well as judge and to instruct. There was never a need to hurry. Some of the younger ones overtook me but they didn't boast about it, they knew my situation and in the end I think I actually know more and have more experience for taking my time.
Its not uncommon for it to take ten years time total for a person to get a black belt if you start counting from day one. You have your own reasons why it took you ten years, you were very busy with lots of other stuff going on.
For people to bypass you in rank, its nothing to boast about. Everybody has their reasons why they might advance faster or slower.
What I think is ridiculous though, is for somebody who wants to advance, for them to take ten years to go up just one rank. For it to take somebody ten years to go from brown to black is a bit absurd.