To the extent that Gene created Star Trek and used it to portray an optimistic, progressive future, he and his vision were good.
To the extent that Gene tried to take credit for the contributions of other writers, he was an asshole.
To the extent that Gene posited a future in which all races and ethnicities were equal, Gene was an anti-racist.
To the extent that Gene depicted a future in which white men were usually in charge, people of color were relegated to stereotypical subordinate positions such as "space driver" and "space secretary," in which brown men were seducers and corruptors of white women (Khan), and aliens were coded as Yellow Peril In Space (the TOS Klingons), Gene was an unintentional, unconscious racist.
To the extent that Gene posited a future in which men and women were equal and women had control of their lives and bodies, Gene was a feminist.
To the extent that Gene depicted a future in which women were passive, easily frightened, too emotionally erratic to assume command of a starship, and constantly sexually objectified, Gene was a misogynist.
To the extent that Gene served numerous combat missions during World War II and saved many lives after a commercial plane crash, he was a hero.
To the extent that Gene was a serial womanizer, carried on multiple affairs, may have practiced the "Casting Couch," and may have sexually assaulted Grace Lee Whitney, he was a predator.
To the extent that Gene posited a future in which humanity had outgrown greed, everyone's material needs were met, poverty was long forgotten, and there were no more class divisions, Gene was an anti-capitalist.
To the extent that Gene tried to cheat his collaborators out of the money they were owed and was himself a greedy rich SOB, Gene was a capitalist pig.
To the extent that Gene imagined a genuinely progressive future, Gene and his vision were good.
To the extent that Gene imagined a world where the things that make us fully human were no longer present (e.g., nobody mourning for their loved ones anymore), Gene was a fool trying to use his fiction to escape the pain he had caused his family in his own life.