Christopher West put it this way.
The only essential difference between men & women:
Only men produce sperm and become fathers.
Only women produce ova and become mothers.That is the essential biological difference between a man & a woman.
So, unless priesthood has something intrinsically to do with maleness - which involves producing sperm and becoming a father,
then it's simply a matter of unjust discrimination to say that women cannot be priests.And that's exactly the point!
Priesthood has everything to do with maleness - which involves producing sperm and becoming a father!