Are there specific guidelines to the type of family that can attend family counseling?

I am 20 years old and have recently had to move back in with my parents due to financial and personal reasons. I know for a fact that our small family is not communicating well at all and our family relationship is all but falling to pieces. In order to live peaceable together I suggested that we attend family counseling together to find a way work out innumerable problems with a mediator. I just overhead my parents discussing how "family counseling" would be a joke because I am 20 (a legal adult) and therefore the counselor would not see us as a family. My father was saying that family counseling is for families with children of course under the legal age. Is this true? I disagree because for an unknown amount of time I will be going to college and living under my parent's roof. I will be supported entirely by them and even though I am legally an adult, technically we are still a family living together. A family that needs counseling to peaceable exist in harmony. Basically my question is: Do you think "Family Counseling" is only for families with children under the legal age? Do you think a family with a college student living under their roof who is 20- Do you think it would be absurd for that family to go to family counseling?