The biggest hurdles that must be overcome to embrace veganism are cultural ones.
I think people can pretty easily tell that animals have degrees of intelligence and emotions, and that people can also identify the cruelty that comes from captivity and bondage. Neither are particularly hard arguments to make.
The struggle comes from getting people to accept that the alternative is sustainable. People are conditioned to a society where eating meat is seen as healthy and essential. Even manly. We employ this myth that vegans are frail cultists fueled by hysteria. That if a meat-based diet was good for our parents, their parents, and so on, it must be good for us too. Or that a vegan diet is too inconveniently limited to only vegetables and tofu. That if we went vegan, we'd become outcasts among our friend and familial circles.
People have always become experts of mental gymnastics when defending the status quo. With veganism, the fables are no different. Guilt and blame only serve to make people double-down on their axioms. Real change requires honest dialogue and education, and that's a much slower process. Psychological hurdles require more delicacy to maneuver
