This will change over time just like it has with every other belt. It's a matter of market saturation.
It starts with "bjj is a special martial art. Even blue belts can KILL YOU!"
Than it became, "Blue belts can be good, but some of them suck. Purples! those are the guys that are consistently good!"
Now it's "Blues don't know sh!t. Purples are usually good, but their are some who got their belt from time in service, but brown belts are always legit. ONE HUNDRED PERCENT."
VERY soon it will be "Blue belts are handed out like candy, purple belts can be kind of good sometimes, some guys get their brown belts out of pity, but NO one gives out a black belt unless it's deserved.
And in the not-to-distant future it will be "So what, he's a black belt. I know black belts that suck. What did the guy win?"
You will see this amp up as the pity blues become pity purples and than become pity browns. Two guys join. One guy trains consistantly, the other guy inconsistant and not a natural athlete. You promote them together, but the skill gap is there. Now the inconsistant blue belt is being tapped by inconsistant white belts, so now you gotta promote the inconsistant white belts to blue before they're ready as well as. The blue belt never gets more consistent and soon he is given a purple belt out of pity because his motivation is clearly gone, especially since his consistent friend is doing so much better.
This continues for years until one day you have a school full of people who would leave you clueless on their rank if none of them wore belts. At the end of the day it doesn't really matter, since if the instructor has done his job right, he's created a nice family profitable atmosphere.