If 1% of the population imagine that they have a “gender identity” there is no obligation on the 99% to humour them to extent of agreeing that
a) they believe such a thing exists and
b) that they have one as well.
I have a slight problem with the first part of that since we know that trans people can experience acute and crippling suffering around gender issues, so on purely compassionate grounds I'm willing to listen to how they express and frame those issues, and medical and professionals are surely duty bound to do the same.
Totally agree with the second part though, and with other comments above along these lines. Basically psychologists, academics and the media seem to have gone from recognising that "a small minority of people identify as the opposite gender to their sex..." to assuming "...unlike most people, who identify as the same gender as their sex".
Noone ever seems to have stopped to think about whether that second part is true, or to have applied any kind of scientific method to it. A cisgender identity is just what you're told you have, unless you take deliberate steps to specify otherwise - which is ironic considering that the whole business developed out of a desire not to presume things about people's sense of self and gender but to acknowledge their own definition and agency.
Now it's like any attempt to even address that second part of the ideology is taken as an attack on trans people. Like in order to not be "transphobic" it's not enough just to treat trans people right, listen and try to understand their views and support accepting them for what they are. You also have to sign up to a whole load of pseudoscientific codswallop about everyone else and refrain from questioning it, even where trans people aren't involved. Madness.
I've quite often asked people, in real life and online, whether they have a gender identity and if so can they describe for me what it is. Mostly people just seem to go quiet and hope someone else will answer the question. I think most of them are as mystified as I am by it but understand it's the sort of issue where you can easily get caught out saying the "wrong" thing. Only occasionally have I got any kind of considered, cogent reply.
To be fair, that has happened in the affirmative in a few cases so it seems to be something that a few people find useful or accurate to describe how they think/feel about themselves. I'm just not convinced it applies to everybody, or even most people