On the surface, the Moritz case was more small ball. He had been denied no more than six hundred dollars in expenses. There was no apparent glaring injustice to women. Marty and RBG could see beyond that. The government was senselessly denying a benefit to someone purely on the basis of gender. If the court said that was wrong, the precedent set would open the door to a broader recognition of gender equality.
This is why it is so important to NOT settle cases just for the money! The law wont change if we don't fight it!