You are not alone with that view. A lot of people have resigned in the past few months. A steady trickle have been suspended or expelled - and in every case I have seen details published it has been for online criticism of Zionism, support for BDS or for attacking the actions of Israel as a state - such things as the annexation plans, home demolitions, detentions without trial (including children) and murder by the IDF. When Labour adopted (unlike most parties or states) the IHRA 'new' definition of antisemitism its supporters went out of their way to say it would not be used against critics of Israel and that 'nothing had changed' there. They lied. Although I imagine Starmer will be very happy to see more anti-racist supporters of Palestinians walk away or be pushed out. He talked in the election hustings of having 'an ethical foreign policy' - but not much sign of that.