He is cruel. She is weak.
Here is a crude yet insightful parable, with the exceptions detailed afterwards.
Men break because they are cruel, callous, and irresponsible. Women break because they are weak, vulnerable, and justified. These biased perceptions are projected naturally, creating standards that are unfair and unjust. When a man breaks to weakness they are perceived as irresponsible. When a woman breaks into cruelty they are perceived as justified. Both instances place the onus of bad behaviour on the man, forcing him to apologise for his unfair shortcomings. Why would a man talk about his mental health, when it is his fault he didn’t live up to the artificially high standards? No, he just needs to try harder to hate his insufficiencies more, it is his fault he falls from the pedestal, that callous irresponsible man, it is no wonder he eventually snapped…
Funnily enough, these biases strengthen themselves. They keep women weak and vulnerable. And men cruel and callous.
Naturally there are exceptions to this. I also suspect this may vary according to personality temperaments. Perhaps the more disagreeable and conscientious the partners are, the higher standards they hold each other too, with these biases affecting the perceptual cause of failure, rather than the situational cause itself.
This is not to deny that there are unfair standards that men hold women to, too. Such as the need to be submissively perfect and beautiful, which when they break that mould, men can consider them bitchy or nagging.
The problem and solution to both seems to be the same. Do a mutual meta-analysis when an exception throws, and together identify if an unfair bias did occur or not.
Sometimes people’s biases are accurate, that sometimes a particular man is cruel, or a woman is bitchy, in which the onus may be on them, but sometimes people’s biases are not accurate, in which the onus may be on you.