If you are a female and only date other females and clify with being a ?

Why does there have to be a label placed on oneself, and why do most female/female relationship end up being a femine and more butch/manly looking type? If your a femine type of a gal, and your into a manly looking woman, why not be with a MAN, or better yet why couldn't you just be a female dating female.... where no one takes on a distinction?