I want to add another source for Colin Wright's refutation of these ideas, a twitter thread he made a while ago: https://mobile.twitter.com/SwipeWright/status/1124406797916409856

The spectrum idea is silly on many levels. Sex is a means of reproduction found in a broad range of unrelated species, ranging from fish and plants, to insects, primates and all the way up to turkeys. Even with interesting variations, like the oft-cited clownfish and seahorse (and I guess mermaid, I'm sorry, I mean mer-individuals of unspecified gender) it still comes down to male and female, or small and large gamete production. With regard to intersexed conditions or DSDs, these are not an indication of any kind of spectrum. Many conditions loosely termed intersex still result in male and female individuals, so those individuals fall squarely in one of the two the bimodal sex categories: male or female. Other dsds, where differentiating between male and female is not clear and reproductive health issues exist, these are not on any spectrum. They simply are disorders that have been dealt with horribly historically by the medical profession. These are around 0.17 (or is it 0.017?) % of the population. Basically our xx xy bimodal distribution of individuals is clear cut for virtually everyone.

But, most importantly, gender has nothing to do with sex other than the presumptions made about about sexed individuals about things outside of the realm of sexual reproduction. Sex refers to reproductive capacity, gender refers to the BS not directly related to reproduction, BS that was entirely made up from each cultures varied assumptions and expectations about how sexed individuals should act. "Gender" is just a neutral sounding sexism.

Another great place for info debunking genderist's arguments is Paul Cockshott's blog: http://paulcockshott.co.uk/oldwp/Butlercritique.pdf