If this is your first world it's probably not so bad. It's a slow speed which allows for plenty of time to hone your skills and the quality of players is pretty mixed. There are some very good players and there are some god awful ones too (like me) lol..
Biggest problems imo is too many peeps ghosting, some of them were top notch and any world will miss good players. There a lot of simmers too which is never good. Add to that the amount of inactive players that all of the alliances appear to have a problem with and it's not so good.
As I said earlier if your enemies message you asking you to stay in the world (that was when I was a bit fed up and considering leaving Nicaea) it must be pretty bad! lol..
That said I'm here for the long haul win or lose and will fight til I'm victorious or dead. Just wish a few more peeps had the same attitude as that is what this world needs..
the reason people say the world is bad is because its speed 1, so its not as fun as faster worlds, but takes less time and effort. Therefore, most of the "elite" players have the time to play faster servers, and so there are less players and lower quality on average. This means there is less competition, hence people say the world is bad.
As Brir said there are some great players here; just not quite as many as some faster worlds, although there have been much much worse ones in the past.
You are allowed to play in more than one world at once, even though it can be a bit confusing at first. Faster worlds have a different flavor. Why not join a faster world as well (speed 3, unit speed 3) and see for yourself?