@toddo it's sometimes used to foster a sense of community and alliance, e.g. I am not a lesbian or trans but I ally myself with them and recognize that we're fighting a common enemy, and that policy solutions that benefit the most marginalized of us benefit all of us. I tend to use it and queer interchangeably. But policing how other people self-identify isn't cool, and how you identify is personal to you, so if you don't identify as LGBTQ and prefer a more specific term, cool
I agree with @ohyeahlasers it's just I don't know why in the US it's so common to leave the (biological) intersex people out of the #LGBTIQ+