Good observation. I've see the same thing on numerous occasions. I used to be a Leftist activist. Basically I was an idealist and useful idiot for Marxist totalitarian types without knowing it. Over time, common sense started creeping in when I saw how dysfunctional these movements and activists were and I left them. I noticed that many of the protests and movements were led by these aggressive shrill women you describe, e.g. Judy Rebick and Sue Collis are two famous (within activist circles) women in Canada who are professional activists of this kind.

There is not a shred of reason in these movements. It's entirely emotion-based. In the 18th century critics of the same use of emotion by charismatic preachers called it "enthusiasm." Famous demagogues have learned to excite the emotions in their speeches, most notably Hitler and Mussolini. You can get swept up in the group energy and not give any thought to why you're there. And it can be dangerous if the mood of the group-mind turns violent against a scapegoat: it's an opportunity to vent repressed aggression, which according to Freud all human beings have in them.

Leftists at pro-Hamas protests have not researched or thought through the issue honestly. If they did, they would not be there. They conflate the issue with their Marxist teachings against colonialism, not realizing that Jews have been on that land for 3,000 years and all the hatred by the Arabs has its roots in religious hatred, expressed as jihad. It has nothing to do with "oppression" or "colonialism." These tropes were superimposed by the KGB and PLO in the 1960s during the Cold War, then promoted by Communists like Ilan Pappe and Chomsky.

Arabs grow up with this hatred as part of their identity. Combined with the activism of the feminist types in the West, it's a bad combination. The feminists give Hamas a pass on their raping and mutilation of women, demonstrating the moral bankruptcy of their movement.

Jihad is an unstoppable force in the Middle East and now stupid Leftist leaders in Europe -- and now Canada and Australia -- are importing it to the West by bringing over military-age jihadis. It's insane. The jihadis view this weakness of the West -- Leftist ideology -- as a gift from Allah. Leftism weakens us and they take advantage of it. Look at the recent riot in Leeds. Why were such people ever allowed to enter the UK?

And who leads these Leftist movements against Israel, or any number of other questionable causes? The so called liberal (or more precisely illiberal) women, the ones with the shrill voices and cold hearts. Everything is framed in "intersectional" terms with their own specialized Marxist jargon. They form endless planning committees to further the cause. I would go so far as to say it's a kind of religion, but certainly not a good one. It's quite dangerous. They see themselves as heroic figures in a cosmic war, but all they are doing, as they have done with feminism, is destroy that which is good within Western civilization.

The West allows for free speech and can take a lot of dissenting opinions (as it should be), but these protests are not presented in the manner of rational debate or reasoned argument; they are aggressive, sometimes openly violent, lynch mob style attacks meant to demonstrate the power of the collective. The motivating force is not justice; it is the acquisition of power for its own sake, through the mob.

On a lighter note, some of these protests are hilariously stupid and laughable. The chant "hey hey ho ho [designated target] has got to go" for instance. You can find a number of them on youtube. And the people who attend them look like inmates from a lunatic asylum, and in fact they are that: in my time in activism I learned that about half the people in the more radical circles were "psychiatric survivors" as they called themselves and they lived off government disability payments for being crazy. They used this money to support their full-time activist lifestyle. Taxpayers were paying them to sow discord and Marxist nonsense in society, in other words.