Noonian Soong wanted more than to prove the naysayers wrong. Even perfected, a positronic brain was just a thing. Sooner or later, someone always came up with a better thing. He wanted a legacy. A hundred years after he was dead and gone, his little girl would be the director of the Daystrom Institute with a Zee-Magnees on her wall and still receiving accolades for her groundbreaking work in cybernetics, and he wouldn’t be just a footnote in a textbook - he would be her father. Critics be damned; his life’s work would speak for herself.
And if his first attempt wasn’t quite what he’d hoped— well, that was one advantage cybernetics had over biology. He could keep trying until he got it right.