He only cared about making money. We've seen plenty of people sell their souls for a few extra tax bucks, so it's not a far stretch. He's made a lot more than he lost, so he probably still thinks it was worth it.
He activley spreads misinformation that put his followers in danger, and blatantly false conspiracies that spread hate and distrust. His outright lies have made him rich and made the world a worse place.
The post truth world that he and his type have cultivated is not one condusive to democratic governance and his blueprint is not a hard one for a litiany of con-men and snake oil salesmen to follow in the social media era.
As has been mentioned before, it is a high bar to prosecute/litigate such behaviour. Protections for speech and the press are strong for a reason and we do not want to erode that.
Some of my childs teachers have had class lessons dedicated to critically evaluating the validity of sources... but I think it needs to go further than that. Starting in middleschool it should be part of many subjects cirriculum IMO, and I think a whole class should be dedicated to it as a junior or senior in HS.