Alright so it appears the crux of the issue is that this was a 600 word submission which was unable to qualify those features and thus the vague nature of them are populated by our presumption. As a MUD player and currently an active developer I can envision how I might implement these features and thus the shared experience touchstone that Griatch and the Judges shared enabled us to interpret his intentions.
That's cool but it doesn't help you, so I will do that now.
1 - Activities: I believe this game would have some kind of "meta-plot" which is a staff guided narrative which gives context and plot hooks for players to use in their own storytelling / roleplay. This also gives direction to what they should be doing with their characters to achieve their goal.
Example: The Empresses Island is soon to be hit by a tropical storm. Some believe that it is natural, some believe it is the Empresses displeasure with the people, while others (the commoners and lesser nobles) only wish to protect their lives and holdings before it hits. This meta-plot which could last anywhere from 1 month to 6 months would give a sense of impending disaster. People would be making deals with each other to pool resources to reinforce buildings or build storehouses for goods as the storm might wipeout their ability to produce goods for awhile. Commoners would be driven to a higher level of productivity. In fighting between the nobility could see commoners used as saboteurs and thieves to destabilize another nobles plans to weather the storm. Some could try and curry more favor believing that if they are high enough that the Empress herself would somehow "will it" and their holdings would be safe. So on and so forth. Meta-plot provides direction which generates activity that is relevant to the story and narrative and setting of the game.
2 - MUD features tend to be tweaked after implementation because of their inherently automated status and because unlike many of the MUSH RPG systems they were not developed by professional game designers, thus mistakes are made. It is widely accepted that this would happen based on player feedback and staff's ability to see the bigger picture. If there were any significant like game changing updates required to these systems there'd likely be a discussion (privately) between staff and afflicted players to somehow ensure their game experience is not ruined. You know tweaking their skill list, providing them with extra skill points or providing them with extra money in a one time "compensation". Depends on the feature and the game design.
3 - For you to Understand why Usurper was "groundbreaking" and basically won first place I will impart upon you some MUD history. Where MUSHes took the more tabletop approach and I think we can all agree MUSHes tend to have stronger emote/pose cultures and more collaborative storytelling. MUDs went into dungeon crawling and combat and more DnD-ish direction. Action was tied to Story and as such I would say a fair portion of MUD players are inherently combat-oriented. Now when the RPI (Roleplay Intensive) sub-genre of MUD was born this was basically a step towards storytelling and roleplay supported by coded systems and action.
Basically it was a more mature storytelling medium within the MUD genre itself. Still combat focused but with automated systems for crafting, medicine, travel, and economies (though they are objectively all bad in my opinion). Usurper is the next step in MUDs journey to a more mature narrative style. It is what I would call a middle-ground between MUSH and MUD. Something that is inherently social and intrigue driven with the automated systems to support actions and combat, but they are supportive to the social and intrigue aspects. Currently there is no game (which I am familiar with) that supports this in the MUD genre.
I hope this helps bring to light why Usurper is so intriguing for us on the other side of the table and why it actually makes me pretty happy that you say you'd try it, because that's exactly why it's special. MUSH players would try it and it's a touchstone our communities could share.
PS - Usurper is not in development in any form what-so-ever. Griatch merely entered the contest and had the idea. He is currently busy developing the Evennia engine which works for MUSH development and MUDs and MUXs too!
EDIT - Clarification. I believe the majority of MUD economies are objectively bad. Not the automated systems as a whole.
The commands are way too archaic for my taste. 
It's just that I see so many interesting stuff from the other MU* worlds when talking to Evennia developers (which are really from all over) that I often try to bridge the gap.