Grandmaestro: I disagree (respectfully)...
A lot of my ratings have got pretty low at times, but I like to fight back. The way ratings work is that, as your skill improves, you can always climb up as high as your skill takes you. I enjoy that fight. It would be misleading if you just "reset" every time you lost a few games. Right now, my goal is to get all of my established ratings back over 1500. I think that the reset idea isn't valid.

emmett:I totally agree.  Besides, since the very first time you play a game your rating is determined as the rating of your opponent plus 400, it's very easy to misuse the resetting feature.  Look at this graph for example.  As you can see, my skill for backgammon is around 2150-2200 but my rating went up to 2528 in the beginning.  Now, if I can reset my rating, I have the opportunity of getting to 2500 again in no time while it'll take me quite a long time to get to that from where I am now.

King Reza: resetting a rating also makes it much easier to boost someone elses rating.

play a few games, gain a high rating (if you fail, reset and try again), lose to a friend, boosting his rating, repeat this :)