But what if someone strongly believes that biological sex and gender are inseparable? I suspect that the majority of the planet believes there is only male and female, and that it's fixed at birth. That doesn't seem so hateful to me.
The whole point of this is that you (or codes of conduct, or communication guidelines) cannot both insist on accepting other peoples' pronouns and also claim not to discriminate on the basis of personal beliefs. You have to choose one or the other, and I think it's more reasonable to choose the latter in most cases.