I have to agree strongly with the "grinding" comment. However, I must take it a step further.
IMO, (maybe not your opinion) all RPGs, MMO or not, are all about grinding. Its all about the same repetitive tasks over and over again for an often worrying number of hours.
I fell victim to this (Runescape) once. Never again! 0.0
I did however try that Tale In The Desert 3 game and got sadly drawn into its complexities. I bailed out (fortunately) before any serious hours were wasted.
I'm not saying the games arent fun (indeed, the pursuit of levels, skills and glory are typically a matter of adrenaline no matter the monotony) however I feel that these games (RPGs) attempt to add so much 'depth' to their games not to increase enjoyment but to increase the number of hours of gameplay they can wean off detirmined players.
For instance, the desert game. Its scale and complexity are admirable and the game designers have done a superb job. However, and I quote this from a player I talked to, "This game (tale in the desert) is not so much a game but a lifestyle." His comments are certainly justified. Having only glimpsed at the many layers both within the game and upon their Wiki page, it appears that a player must spend countless years playing the game before he/she can achieve 'greatness'. If that is what you are looking for, then fine. I quickly realised that playing this game and recieving any enjoyment out of it would have required the abandonment of all the other games I play (including Blockland). If I had a social life I would have to lose that too.
Summary:
RPGs of all shapes and sizes, whether multiplayer or singleplayer, gain their popularity and population by creating false goals and odd aspirations for the players in the form of digital levels, items and fame. It is when these players realise that the goals are not real or are simply there for the sake of it that all interest is lost and the only possible remaining attraction may be the social interaction with other players which, while extending the life of many multiplayer RPGs well beyond comparable singleplayer titles, still falls short of meaningful gameplay.