It has to be for them (people who believe there is a gender pay gap) to try and make any change. There are plenty of examples where pay is different regardless of gender: sports and entertainment would be two big ones.

With sports, people are payed differently even if they fill the same position on a team. Why? They aren't the same. They bring different skillsets. It's the same with movies. The main character will make more than someone 20 spots down in the credits list. Someone with a well-known name will make even more. All of this wage difference that can occur across genders.

But with tech everyone should be paid the same if you share the same title regardless of how different you are or how much value you bring to the table.

Edit: To clarify, I have no issue with a company removing any pay difference between employees. I only have an issue with those who think paying people differently is inherently a problem.