On the one hand, I do sympathise with that point of view.
On the other hand, it really does highlight how brave JKR has been.
A sizeable amount of the abuse JKR gets comes straight from America, because she's incredibly famous globally, and because she was adored by all these American millennials who are now terribly upset that their former heroine has turned out to be A tRaNsPhObIc BiGoT.
Even many of the people in the UK who have jumped on this bandwagon would probably been unaware of it if they hadn't seen the tidal wave of abuse about JKR coming from America, from people who are incapable of having a civilised discussion with people who disagree with them, and who are completely fucking ignorant of the laws and policies in the UK which JKR is actually tweeting about.
If Dawn French, and not JKR, had been the one to lead this fight, it would have gone under the radar of American millennials.
Even now, if she started tweeting the way JKR does, she wouldn't get as much abuse because most of the real zealots are in America and don't know who she is.