Not caring about men is also built in to our biology, sadly.

But so are our brains that allow us to realize this and react to it. Western society gave men certain perks to help make up for the expectation of dying in war, risking their lives working, etc. Marriage helped to ensure that a great number of men didn't go without mates.

When you take all of that away, you're left with beings that are not only being given a raw deal but realize that they are being given a raw deal and are more likely to turn to violence against themselves or others, which is not exactly the recipe for a healthy society. It's also why feminism and related ideologies are so concerned with emasculating "angry (white) males" and rendering them harmless so that they don't have to face the issues they are creating.