I think the key issue here is not the rating system, but the fact that there is an incentive to play at a lower rating for leagues. I took a long period of time off from tennis, and just started to play leagues last year. It is actually a lot of fun, but IMHO it has drastically changed the game. I don't mind the ratings games as much as the new "line is out" philosophy which is common on many teams. The rating system should and probably does do its job assuming its not gamed. In the greater scheme of things there isn't too much difference if a low 4.5 is on a 4.0 team or vice-versa. The real issue is people intentionally gaming the system. Even in this case I don't know that I get it too much. Winning a national 3.5 championship when your a 4.5 player seems pretty lame to me.
My particular case is probably somewhat common. I was a mid 5.0 when I was young, but took many years off and put on 70 pounds. I self rated as a 4.5 last year and had a winning record but got bumped down to 4.0 which was probably a mistake based on the way I was playing. Over the year I decided to get my game back into shape and lost 40 pounds. At this point I am nowhere near a 4.0 and improving. I've played a few matches so far this year, and based on the results I'm pretty sure my rating is nowhere near the 4.0 level anymore. I'm playing both 4.5 and 4.0, but mainly focusing on 4.5, but I guess as lame as it is I too am continuing the 4.0 play.