Humans need at least some meat to survive. [...] It causes long-term, serious harm to people who do not supplement their diet with at least some meat. [...] completely cutting out meat is bad for you.

That is not correct.

Advocating a vegan (or even vegetarian) diet is ignoring science and how our bodies function. [...] Pure veganism is a cult that ignores science, diet, and common sense.

To the contrary. It is very much supported by science. Are you interested in the scientific literature? I'll happily share.