>>215431067
>>215432621
The real reason is much simpler. Writer was a guy who lived in a Ming dynasty and target audience for the novel were most likely nobles and Ming Emperors court. Writing Cao Cao as the hero of the story would quickly earn him accusations of fostering rebellion against the Emperor and get his waist chopped in half. So he had to keep Cao Cao as the villain despite the fact how much he loves writing Cao Cao as this charismatic and smart conqueror dude who really liked other smart ambitious dudes.