Put things into context. People CD, NMR due to overcommitment or real life issues. Back when I started playing diplomacy in the days of playing by e-mail it was considered normal for a phase to take 3 weeks. That's right 3-weeks. The site that facilitated this also offered fast diplomacy on 1 and 2 week turnarounds, but you needed to have successfully finished a game on the 3-week a season first. In addition to this if you CDd or NMRd you'd better have a damn good excuse because otherwise you would be black-listed and not be allowed to play another Diplomacy game, ever, period.
So jump forward a few years and diplomacy judges appeared, and then phpDiplomacy shows up on the scene. And holy-shit! all of a sudden there is a huge community of players somehow managing to play games with a season turn-around of as little as 1 day... and then live games appeared on the scene! This was awesome! A real change in how Diplomacy was played on the internet.
One side effect from this is that all of a sudden, many games started to become disrupted as new players realised that, again, holy shit!, Diplomacy actually takes a significant bit of effort and commitment to be an active contributor to the community.
So efforts were put in place to prevent a newbie from joining up to 10 games or more in his first hour. RR restrictions are simply the latest iteration of dealing with the issue of encouraging players to commit to the game and not ruin a game for other people who have committed to it by CDing. In this internet connected world we can forget, I think, the value of well constructed negotiations that take place over a period of time. I know I don't always fully commit to games that I play, but I try my best not to NMR or CD. I'm fairly sure that I've found my balance with the amount of games that I can legitimately commit to at any given point in time.
One of the better suggestions that I've heard in this whole discussion is the idea that password protected games be exempt from RR requirements.
I don't think that the community would like to move back to permanent banning for players who CD, but the RR process seems to be doing its job, if somewhat imperfectly, in providing a restraint, as well as an effective punishment, on players who are unreliable in their commitments to games.