It's not that such a prospect isn't interesting, it's just that it inevitably leads to the kind of feature creep that leads to bugs and outright brokenness (insert reference to SimCity). Maybe I'm in the minority here, but I'm not at all against games that just end, rather than try to shoot to be a world in which you can fully 'live a life' and in which the world is infinitely evolving. Good single player experiences are bespoke storytelling affairs.and to abstract it out to accomodate MMO interaction would seem to necessarily dilute it.
In any case, it's hard to imagine an RPG world that could be designed successfully to be a MMO and a good single player experience. Luckily, it wasn't, but it was basically the end of Ultima as a series, though arguably it wasn't a causation. I remember when UO came out.I never played it but I wondered if it would be the end of good single-player RPGs. Multiplayer Online Game - which can also be played solo player / offline