I think the appeal of Medieval Roleplay is whatever people make of it. While I may be biased here, being the de facto writer of the original's, and likely this server's lore, my favourite thing in the server was coming up with this fictional world and watching people interact and expand the lore. Some additions were great, but that can't be said for all of them.
Hosting MRP was always somewhat of a balancing act which lead to countless features being introduced, reworked, removed and near bi-monthly rule revisions. If we were to restrict the players' freedom too much, we'd have ended up with a glorified chatroom, if we didn't we'd have had a loosely medieval simulator.
I'm gonna use New Vegas to draw a parallel. I hope I'm not spoiling the game for anyone here, but if you side with the NCR, you'll eventually get a quest to deal with the Great Khans, who are a group of raiders pretty much. One could just go in gun blazing, and wipe the entire faction from the Mojave, or they could completely resolve the situation diplomatically, both of these solutions are valid ways to progress the story and neither of them are punished, the course of action is entirely up to the player's decision. You can't really have something like this in a game where each characters are players. If we were to tell people that they cannot wipe each others' characters out, we'd restrict their freedom, if we were to let them we'd risk creating a long term game in which you can lose your progress completely at any given moment, so we ended up with an often confusing set of conditions in the rules on how and when could you kill someone.
If you read the previous posts, one can see that people liked different aspects of the game, some preferred warfare, while others preferred character interactions and story progression, and we were trying to appease most of them. Thus, we'd usually have political events so that the leaders of a state could deal with diplomatically, but it often resolved in battles, which the other group preferred.
While we still had a sizable playerbase (for Blockland standards), truth is near the end neither LegoPepper (the original host) nor I were having too much hosting the server, and we were already flirting with the idea of giving MRP a send off and moving onto the next thing, ultimately he decided to allow another Admin to influence the server in hopes of refreshening the gameplay. Although the majority of these new ideas were never really added, they proved to be very unpopular with the majority of the server, this being Blockland, drama ensued and LegoPepper ultimately decided to shut the server down. I don't really intend on pointing fingers, because you'd likely get different results.
(in actuality it was all valkerone's fault alone btw)I'm not really involved or really interested in Sable's server. While LegoPepper and I never intended to (and never did) release our map, or the add-ons, I can't really say we're bothered by the new server, which should be considered somewhat of a spiritual successor or even fan sequel, since it does reuse a lot of our works. I mean it's quite flattering to know that people still play the game, long after we've left the game, you know.
zombies in the bluezone or frostbite were the best roleplaying servers and these medieval ones do not live up to the expectation that has been well-established.
I think people tend to really forget the flaws of older RP's. I wouldn't call Bluzone or WinterBite bad servers, since I've spent way more time on both of those than I'm willing to admit, and as much fun I've had, people tend to forget that in those times there were way more players in the game. The majority of Bluzone players were only there to RP, and WinterBite could afford to install a forum based whitelist system. Other than that in the later parts, Bluzone was a bar themed chatroom for the mentally ill characters, waiting for the next happening, and WinterBite turned into an eventless lesbian dating sim while we were waiting for the Frostbitten update. While the characters were pretty cool to interact with, do people even remember that in the last chapter? You quite literally couldn't have a firearm and the zombies were removed from the map.
Hope this answers most questions.