Some humans did that, and the others found the behavior odious enough to develop social norms against such behavior. Humans have always had many vices, sure. They lie, cheat, steal, murder, etc. That doesn’t define their humanity.
And other societies developed social norms which sacralized and ritualized the usage of such drugs, or which totally normalized them. Again, the idea that there is a single social expression of what constitutes 'humanity' is a very reactionary mindset that flies in the face of all evidence and history.