I don't think they hurt the community, only the rich can afford them anyways. People sell services/time all the time, most of the people who sell clears aren't going to help you for free regardless of your thoughts about clear selling. To me people should have the freedom to play however they want as long as they aren't directly cheating/ruining others' experiences. If anything I think it helps the game stay more active because both the people selling and the people buying would probably quit otherwise. In my opinion an active mmo is a healthy mmo.