Yes, edubs, I have a tought or 2 about this.
First, Paul was a misogynist, he was not "of stable mind". His changing of the law was a family matter to him. Totally under his will.
Nicholas was way too conservative to change what has bee for so long. Legally, Olga could not inherit unless genealogical progression occurred.
That is, all male heirs were eliminated. Hence GD Maria's present claim to be head of the house. Also, NII could not change the succession law with appoval, the Church and government as well as the military. If he had opposed those groups, he would have totally lost confidence way before the abdication.
And, Alexandra, being who she was, I think would not have wanted it changed- male inheritance is primary. Alternatives were not an option. I do not know what was in that woman's mind, but she most likely had other aims for her daughters, rilling Russia most likely not one of them.
Next- Olga herself. Would she have even wanted it ? What would it have done to her future prospects ? A life of secret lovers ? As previous empresses were forced to deal with, as she could not marry a Russian and any foreign prince would excite the masses into even more xenophobia.
Just my POV