The left doesn’t think Jewish people are monsters. They think people who support the Israeli government are monsters.
Because yeah, supporting genocide is monstrous. And one would have thought that Jewish people should be the most sensitive to this issue. And certainly, there are a lot of Jewish people who do recognise how evil the Israeli government is. At least one of the people tragically killed on 7 October was a Jewish supporter of Palestine, and their family came out in the aftermath saying they hoped the Israeli government didn’t use it as an excuse to do…precisely what they have ended up doing. At least some of the many pro-Palestine protests around the world have been organised in part by organisations like Loud Jew Collective and Jews Against Genocide.
Don’t fall for the propaganda that says if you’re Jewish, you must support Israel. Heck, even if you are Israeli or have family in Israel, you don’t need to be supportive of what the government is doing. One of the few good things that can be said about Israel is that it is a fairly free liberal democracy—as long as you’re not Palestinian, at least—and that comes with the freedom to be critical of the government. A freedom you can and should exercise when your government is committing genocide.