They're not saying "X is bad because X is bad", which would be begging the question.
They're saying X is bad because it leads to Y, and Y is bad. Y being bad is supposed to be common knowledge, so they didn't go into detail.
They're not saying "X is bad because X is bad", which would be begging the question.
They're saying X is bad because it leads to Y, and Y is bad. Y being bad is supposed to be common knowledge, so they didn't go into detail.