They've always been like this. It's the reason why the Miners' Strike is a "historical political moment", but the Gate Gourmet strike isn't.
I spent my twenties heavily involved in left wing politics and, fundamentally, what I found was a "movement" of middle class/upper middle class, over-privileged individuals (largely male) , whose radicalism was fuelled by a deep resentment that they didn't automatically slide into positions into positions of power and influence when they finished their education. And this was over twenty years ago.
That's why they hated Tories because "Tories" were the ones they thought kept them out of what they thought was their right to power and wealth. I never met one left wing white activist that had been to a comprehensive school or lived in a council house. And they were pretty much terrified of working class males, a fear they span round by dismissing most of them as fascists, Nazis, thugs, idiots etc.
And they'll jump on any bandwagon they think will deliver them to the life they secretly believe they deserve, no matter how much their involvement may destroy said movement.
I was lucky to be of an age when old school feminists and race campaigners were still around and would talk freely. I remember one particular Amazon in the field of feminism and race relations telling me that certainly well known left wing cultural names at the time were "full of shit" and that they weren't allies. I was shocked back then by her words, but, by God, she was right.