A key issue in this is that the screening process is completely opaque. I have acquaintances who have tried to get visas to the US, and it usually takes several attempts - with nothing really changing in between. It mostly comes down to the exact immigration officer working somebody's application, and the waxing and waning of the moon.

The reasons given are extremely broad, so it makes nuances like this largely irrelevant. If an immigration officer perceives their duty (or maybe it's just their own personal opinion) to be to reject applications which are critical of Israel, then that's exactly what they're going to do. And you have no ability to appeal decisions, not that you'd even know what caused those decisions.

FWIW the people I'm referencing were also completely upstanding, educated individuals with high competence in English. It's a great way to make one loathe the double standard given to people who just illegally cross the border. Even moreso when you consider that each of these applications costs hundreds of dollars in places where that's often a rather substantial sum of money (just as it would be in most places in e.g. South America).