Re: All else being equal...
Whilst I have no doubt there is genuine inequality between men and women in the workplace, calling for 'equal pay' is not going to work; one needs to look at 'equal cost' - how much employing a person costs.
On that basis, women do cost more over their working lifetimes. many take several block of maternity leave (and sorry, the existence of a splitting option in the UK does not mean the leave is taken even remotely equally). This requires backfilling of roles, for those periods, which can be expensive, and many women go part time or flexi time, which require more staff to cover days / core hours. Women then have the temerity to live longer, costing more in pensions.
None of this is unreasonable behaviour, but it does mean that a cohort of women will cost more than a cohort of men. If you want true equality, then that is equality of cost, and one of the very few variables available to the business in that cost is wages.
That absolutely does not mean that first like Oracle should use this as a smoke screen to take the piss on wages, but it does mean that 'equal pay' is, in fact, inequitable, and for this reason meets resistance.