Beyond the present day usage of “gay” in a derogatory way, before it was the umbrella term for the LGBT/Queer coalition and also specifically a term for homosexuality, it was a term that for centuries along with its literal meaning as “happy and carefree” had a connotation of immorality and had by the 17th century picked up the usage of being specifically sexually immoral. Quoth Wikipedia: “A gay woman was a prostitute, a gay man a womanizer, and a gay house a brothel. The use of gay to mean ‘homosexual’ was often an extension of its application to prostitution: a gay boy was a young man or boy serving male clients.”
What became known as the “gay community” rallied around the previously derogatory and euphemistic term “gay” particularly with the rise of radical Gay Liberation movements around the 60s, as previous homophile movements and organizations settled more into assimilationist politics (see: the deradicalization and eventual splinter of the Mattachine Society after the ouster of its communist founders).
The exact same thing was done with “queer”, it was a term rallied around and reclaimed by radical liberationist movements.
To try and deny our communities our own language is to spit on the graves of those who didn’t sit around to be somewhat accepted into the status quo if they could cover up their differences but fought tooth and fucking nail for our rights to be loud and queer. It is an assault on our history which we have to fight to even pass on, even in this age of unlimited information at the tip of your fingers (because *some* people are content to not do any amount of actual fucking research and just spout utter bullshit about LGBT/Queer history and the etymology of our identities, and while some inclusionists are guilty of spreading misinformation like this it’s nowhere NEAR the amount that exclusionists do). It is carrying on the history of throwing anyone who literally cannot assimilate under the bus to grasp at the chance for social privilege that no matter what is still out of your reach. And people think they’re being revolutionary and radical while they do it.