You're missing the point. All of that is a redundant. All of it. You had a mission from somebody who gave you position to train a slave into a whore. All of a sudden the whore is a better option? Where she wants to be queen of Raana? You simply play along like a good dog.
You empowered an 18 year old. One you were tasked with and have done the opposite, why, pussy whipped. At what logical point have you done it? Because the game made a mission. Yes you still have the feminism ending. Despite a variance of a corrupted Aria.
Again you're in the same position you were, except you empowered a woman. You didn't take it yourself. You didn't rise through the ranks either. You put a woman in charge, and a feminist for the most part.
Not propaganda I wish to indulge
You keep using the word propaganda, like what, you actually think the dev made that plotline as some kind of girl power statement?
The plotline where if Aria is put in charge without much training or guidance from you then she ends up fucking up pretty often as it turns out the skill set for running a covert rebellion doesn't carry over to administering a large state.
The plotline where you take a young woman with great prospects and personal power and can break her down into your personal puppet and rule through her.
The plotline where you can elevate yourself from being just a prominent landowner to a highly respected and titled member of the new government, honoured with statues, acclaim and privilege in excess of what you could normally imagine
And in the interest of engaging in good faith, as to 'at what point your character would consider listening to her and following the missions?' the same point most player characters follow any mission from the characters? A lot of characters have missions attached to them, most people end up doing them, either because it is there, because they are roleplaying someone who cares about their subordinates, because they see something to be gained from helping the subordinate out.
As for what a character might see in helping Aria in particular:
A more equitable future for Ikaanos (if doing a low corruption playthrough)
A powerful position of influence over a prospective new government
Riches and plunder in great excess from raiding not only the palace district but the mastersphere
Opportunities to capture rare and powerful people and enslave them
The ability to leverage your unique position of influence over Aria to shape the new leader and her policy to be favourable to yourself
An opportunity to usurp and oust Mordecai if your character views them as too incompetent and corrupt.
As for why people would take it over just doing the 'normal' quest, corrupting her and handing her over
Because corrupting is almost always the exact same boring outcome
Becuase even in an ideal scenario, you would still functionally just be a particularly notable slave master, your star still tied to Kymanto rather than shining bright alone as a pillar of the revolution
Even when the corrupt Aria option is complete, it is likely to be far less interesting than taking part in a history defining revolution.
Like you might see more people take the corrupt Aria route once it is a bit more fleshed out, but I doubt people are going to take it, even on corrupt playthroughs, because it is just a lot less boring than couping a whole government.