Yes it is.
Demanding equal wages based on the same position at work IS arguing fairness.
You don't have to make demands for something you already have.
Women who do the same work as men, with the same hours and same experience also get paid the same wage (in fact recent studies have shown that women often make MORE than their male counterparts).
If this wasn't the case then not a single company would hire men. Why would I hire a man if I can get away with hiring a woman for the same work but for less money? If the wage gab was true then all men would be fired and replaced by women. Think about that for a minute.