To be honest, the system isn't the problem. It's the people. As a person who was around back then, this current system is a VAST improvement to the old system. It's world's easier to get ahold of a sensei no matter how many people still insist on complaining about it, things are balanced to the point where RPers can go on relatively equal footing amongst each other, getting bios approved and having a bio test organized are extremely easy, and plenty of other reasons.
So why did many people, myself included, enjoy NB more a few years back? It was the people in the system. Not everyone complained about everything that wasn't completely clear or justified, and trust me, if you think that there are unclear rules, or corruption, or favoritism, anything else unfair now then I know for a fact that you would hate almost every aspect the old system.
Basically, the system is fine; much improved actually. By no stretch of the imagination was the old system better in any way except for, possibly, being simplified in some ways. It's the whining that's the problem. I know that plenty of members must have said this before. But it's true. RP back then was more about screwing around then being... so serious.
And like Daemon said, it can't be done anyway. Not only is there no way that the mods would throw away all of their work that is the result of about three years worth of slow developing to get it to the point where it is now, nor should they, but seeing as a thread was just made speaking out against overpowered members... yeah. The old system brings up the possibility of more corruption, more favoritism, and as a result more members angry at the staff for being unfair.