Federal minimum wage increases: why do they keep excluding tip-based profession minimum wage?

It kind of burns me up that a good section of the population makes $2.13 an hour, a wage that has not increased a cent since I began waiting tables almost 10 years ago. We are dependent on people to tip us, yet are faced with people who feel it’s not their duty to pay us, that management should. In addition, we are more affected than most by swings in the economy—people still go out to eat, ride in taxis, etc., however, the money they give out as tips definitely goes down as the economy takes downswings.

I don’t understand why we can’t get an increase, as well.