Honestly why do people do this? Blue ticks who have an established career writing and campaigning etc just make themselves look mean and petty when they do this and they certainly go down in my estimation.
JKR gave great publicity to a certain T shirt maker who was present at the lunch. A sprinkle of fairy dust must have done wonders for her business. But I didn't buy one of her T-shirt's at Filia specifically because of things I have seen her post, joining in with the hue and cry.
JKR also sprinkled a little fairy dust on Standing for Women T shirts. Maybe she just likes the T-shirts. Or maybe she likes to give support to lots of different women who are fighting the fight in their own individual ways.
There's room for everyone, doing what they can in the ways that work for them.