Imagine there is a player with a program and he goes up to 1100 points. The rating is steady. I dont see more than 2 players getting to that 1100 points. That means that the player in question without playing for weeks, maybe he is always at the top because other players are not able to get that amount of points. Is not fair for other players.
I think other sites must do the same.
Look on the bright side. I would suggest you playing against people with a rating similar to yours until you are better ,otherwise it will definitely keep dropping with playing of without playing. And is good also for your strength.
I think this system of dropping down the rating works perfect to me and other players. ^^