Many still believe that the goal of the animal rights/liberation movement is to find more humane ways for humans to make proper use of animals. That would be a noble goal, but it is not what animal liberationists were really after. Rather than supporting animal welfare--which acknowledges the human right to make proper and humane use of animals for human betterment, but which also insists that humans fulfill our moral obligation as humans to do so in the most humane ways practicable--animal liberationists insist that humans have no moral right to make use of any animal for any reason. Thus, when they equate cattle ranching with human slavery and eating meat to the Holocaust, they mean it.
Following this anti-human philosophy would lead to great human harm in many areas, explicitly including the stunting of medical progress, as this column