>>130223988People complain about the diamonds being "redeemed" too easily but that's women's weakness. They are far more vulnerable to emotional appeals and manipulation, even the evilest ones. If there was some IRL woman genocidal dictator, I guarantee you get them to give up on their conquest by finding a sentimental weak spot, like her children, or something she's touchy about, and acting accordingly.
The diamonds are needed for gem society to function, so it's better to change their minds instead of destroying them.
A male villain will abandon everything for their goals. Males have the ability to completely detach their actions from their emotions, or kill their emotions entirely. Goals are more important to males. They will stop at nothing, so there's no choice but to destroy them.
It's like IRL, you need some sort of ruling power for a society. Ideally you want to manipulate this power to your needs, but sometimes, the power is so corrupted by someone hellbent on making their awful vision a reality, that the power needs to be overthrown and destroyed, and then the society collapses.