There is this so-called gender ideology which tries to deny sexuality as something biological.
They basically took the linguistic category of "gender" (in most languages every noun has a gender: masculine, feminine or neuter; people get their gender according to their sex) and made it a psychic category that is somehow orthogonal to sex. Then they moved characteristics of the two sexes (including sexual orientations) to this idea of gender, claiming they are so because of social constructs and while doing so they faded one gender into the other, creating a sort of sprectrum.
Right or wrong this is technically what they did but most of them will always say that's just the way it is without arguing much and be personal offended if you just don't join their conclusions, even if your respect them but arguing for the sake of science.