[KaVir]

Human nature. There's a honeymoon phase where everything is exciting and new, but it gradually wears off, and that's when many players start to look for something different. This isn't limited to muds, or even to games in general, but applies to all aspects of life.

You can encourage old players to return by offering them something new to play with - a special event, a new zone, a new class, etc. It's difficult to churn out content fast enough to keep the players entertained though, so even a very actively developed mud will tend to introduce new features in spurts.

It's very easy to look at an established game, point out all the flaws, and describe how it could be made better. In fact that's how a lot of new muds get started - the owner wants to create something just like the mud he used to play, except his version will fix all the problems.

However such muds almost always fail, because the developer usually fails to recognise the reason why things were done the way they were. The few that succeed simply repeat the cycle, as their players become disillusioned and decide that they can do better.

I've never played Castle Marrach, but I can tell you this much: No matter what design decisions or changes you make, some players will hate them and leave. But if you make no changes at all, the mud will stagnate and even more people will leave. So at the end of the day, you just have to accept that you can't please everyone, and move on with improving the mud as best you can.