Why is it that the real is never as good as it should be?

The Female Quixote holds even today to be an interesting example of social critique. I a not sure that I see Arabella as not having a firm grasp on reality, but instead I think she fits a trope of the unrelenting mythic hero, until the death of her independence, and therefore her power, at the end of the novel. What is striking is that Charlotte Lennox even provides for the removal of most societal norms that would force her hand toward marriage, were she opposed to it. Her guardian wont force her, and she has enough money to live comfortably single should she wish to. It feels as though the ending is Lennox throwing in the towel on her fight to provide a viable female protagonist that her audience can see as surviving and behaving in a socially acceptable manner without a husband. The rather rushed nature of the ending, and the coinciding pressure to publish, might function quite well as a metaphor in this case. Were she to choose for Arabella to not marry, to drag out a courtship or maintain some sort of power over her existence, she might well have felt a need to write to the end of Arabella's life to provide for the extraordinary way that she lived. While single she has the power to defeat robbers, and debate with the men around her, and marriage is likely to take any of that away.
But It occurs to me that the character of Arabella offers up a little more than that. She evokes something of the Shakespearian fool in the novel. She has the ability to operate outside, or at least less restrained, by the societal norms that surround everyone else. From one perspective she might be seen as rebellious, and her readers might agree that one cannot simply view the world however they wish to. From another, however, she seems to represent one of the few people in the novel prepared to do 'the right thing,' versus what makes them appear in the best light. From that perspective, the idea that while the romance may be dead, the characters they offer are a far sight better than one is likely to find in a given circle of people. Perhaps the sudden realization at the end, the loss of the innocence that allowed her to have control over more of the world around her than most other characters in the novel, can be seen as part of the social contract dependent upon the exchange of women. Her refusal to acknowledge that aspect, or even be able to see marriage as that, throws the system into chaos, giving her power, at times, the equivalent of life and death over men. So then I wonder what that acknowledgement might mean in the larger picture?