Earlier quoted context omitted.
You are trying to retrofit current sense of morality onto the sense held by people in the past. What if people during Turing's time actually thought that homosexual behavior was unethical (which I think is not too far from the truth)?
It's not about ethics, it's about beliefs vs qualities. Being gay is a genetic trait, it's not a formed belief system. Whether that was generally understood 70 years ago is neither here nor there. Furthermore, there is the question of liberty. Being gay and performing homosexual acts is a personal choice, it does not hurt anyone else the way bigotry does.
That's some handwaving.
Again, your argument looks at it with present eyes.