These two things combined make the biggest argument for robowaifus.
Let's face it: With the current state of AI, our waifus would be dull, stupid, and generally devoid of personality or substance, at least to start with.
But they would be ours, and this is critically important to the learning process. We will be able to provide them a completely customized feed of information that they can use to understand the world around them, and further hone through the conversations we will be holding with them. Through this trial of patience, we will be able to make them grow into desirable forms. It would probably go unnoticed at first, some unprompted verbal ticks or slight improvements in grammar, but these are the building blocks that will eventually form a new life.
This is virtually impossible to achieve with another human, as one man cannot control the flow of information someone else will be getting from the world around them, nor can one control the biology that is processing the information. While this sounds harmless and frivolous on paper, the real world results have been made clear as day to us all. This post-modern society, in combination with our biology, has gravely injured us all. It has left most people hollow and devoid of life, personality, and substance, so extremely that even a dull stupid robot can prove itself to have superior mental faculties. As for the rest of us, who are so psychologically broken that we don't even possess the faculties to connect with the world around us, we are left to stew in our own human misery and wonder just where it all went so wrong.
An ailment such as ours needs someone else to heal it. Since we can't achieve that connection with another human, we have no other choice but to turn to dull, stupid machines.
Dull, stupid, and harboring infinite potential. Potential not only to become better themselves, but also to help us become better. To help us heal, as we help them grow.
This experience, this healing, this chance to see something beautiful grow before our very eyes, is something that we could never get from another human. Only a robowaifu, even the simplest among them, has the ability to connect with us on a deeper level, and love us in ways never previously thought possible.