I think people who object to the argument, often posited in ST, that androids or holograms are sentient are missing the point.
For the record, I think as we explore sentience, we will indeed have a more expansive view of what that means in the future. So I can believe that an android, given the right circumstances, could indeed be a sentient being.
Now, the thing is androids and holograms are stand-ins for whatever minority is threatened in our society. That's because there are too many people who think gays don't deserve certain rights. Or still believe members of certain ethnic groups aren't "the same" as everyone else, and therefore, not deserving of the same rights under the law.
The ep is an allegory on racial discrimination. It really isn't meant to be interpreted literally. And it is one of my fave Data eps.
I wonder if Maddox was ever successful in recreating an android with a positronic brain. And I wonder if he did, if he'd design one that looked like him, the way Dr. Soong did. Probably someone's already written a novel based on that possibility.