It's conditional, with different answers depending on what you mean by "cult".
For example, if you require a cult to have characteristics like strong leadership, veganism is certainly not a cult.
If you call any organization with some common morality a cult, then socialism is necessarily a cult.
And so on.
By common definitions of a cult, veganism is very clearly not a cult, but some loon might want to stretch the definition.
In this case, the loon would have to accept that speaking English is a cult, at least if he wants to be consistent in his logic.
This also avoids low IQ "discussions" like>NOOOOO WOMAN MEANS CHROMOSOMES! THIS IS WHAT IT OBJECTIVELY MEANS! LOOK AT THE DICTIONARY I PREFER! ALL OTHERS ARE WRONG!