The same reason why in the US we have people attacking trans people (even when they've literally never seen one in person) and why our monopoly laws have gone from "chop them up for the common good" to "you better stop it or we might levy a symbolic fine"

The political window has been shifted so far right that the left's position is "we need to be nicer to the people in Gaza, but really carefully since they'll subjugate us if they have the chance"

It's not an accident, it's a small group of people with a lot of money who are investing it in hijacking discourse for their own power.

If you get on tv and start pitching socialism, you're instantly dismissed as a radical. You can't even have the conversation - people don't understand what that means and will instinctively recite nonsensical talking points, because they've been fed those for so long it would take an intensive college course to unlearn enough that they can have the actual conversation of "would this work better". The vast majority has internalized the idea that "raw dog capitalism is the only feasible system"

It's the same with Israel. They've been fed propoganda so long that you can't have the conversation - they've internalized the idea that Gaza is a bunch of animals who want to kill them, and the furthest left thing you can pitch to them is "well, maybe we should improve their situation economically, but we have to be careful not to let our foot on their neck slip off too fast"

Fun fact - there's a lot of overlap with the groups doing this in the US and the ones doing it in Israel. By that I mean literally the same groups are funding both propaganda efforts, like the heritage foundation