It matters only when it's a negative. Having the top rated badge on your profile gets you a front seat on good contracts. And yes, clients pay attention to it, and it enables you to increase your rates. The only time it doesn't matter is if you don't care about all that.
The rating system has lots of room for improvement, but it is what it is.
Cherry, this is a little off topic but you know having that link in your profile is a violation of TOS and can get you suspended. I would take it out with the quickness.