Well depending on which time I was promoted, two different stories. The first time it was because I wasn't part of any major faction and floated around doing dastardly things as an over powered acolyte, then Jon decided to a training thread with me and boom he was a knight (shortly after I have up on the character unsatisfied with his 'acheivement'.
The second time I was promoted as Zambrano the Hutt... I honestly have no idea but I figure he was doing so well for himself (without being overpowered) that perhaps people didn't notice at first. I never had a dedicated master either so that might be part of why it took some time to get noticed for a promotion.
But on the topic of grinding through ranks, this suggestion isn't about that. This isn't a short cut to UNLIMITED POWER, this isn't some crazy loop around where you get to 'do' things without working for it, it's an additional option for writers who've done the work to expand their horizons in character creation, while at same time placing caps on how far they should be going with the option.
I hope that makes sense, but I can understand that this might be an unpopular idea even if in principle it's for all the right reasons you'dhope for in a constructive suggestion.