I lived through the “take back the word queer” movement, so let me further sum it up
The entire point was to strip the word of the power to hurt us. We embraced it by refusing to be offended by it. We were saying “you can’t hurt us with that word, we now feel empowered when we hear it.”
During this time I saw an interview with a gay man who’d been arrested while wearing a “We’re Here, We’re Queer, Get Used To It” t-shirt. He was put into a holding cell with other detainees who tried to verbally abuse him. They started out by calling him queer but after seeing his t-shirt, and him not reacting to that word, they started stumbling over their words trying to find a name to call him. They finally settled on repeatedly calling him a “sissy” which, by the late 90s, had become a very out-dated slur toward queer men and was a laughable effort by these hyper-masculine and sexist bullies
When they tried to call him a queer it had no power because embracing the word, no matter who said it, had taken away that power
tl;dr We took back the word Queer with the intent of it no longer having the power to hurt us, but people now calling it the Q-slur are giving power back to the people who hate us