It's also a question of proportion.
In terms of humanitarian crisis and human rights abuses, Yemen is not in the same league as Palestine. Syria is not in the same league. South Sudan, Myanmar, Russian actions all over. If you're motivated by humanitarianism, you have your pick of many many other far worse situations.
And I don't think it's just a question of democracy. Turkey is ostensibly a democracy but has imprisoned more journalists than any other nation and bombed the shit out of Kurdish civilians. Nary a word is heard about Turkey. Or Russia etc
I also don't recall there being any demonstrations against Myanmar and its genocide against the Rohingya back in the end of 2017 in the same way there were during the Gaza incursion. And, again, however bad Gaza was, what happened in Rakhine was many many many time worse. One million people were displaced as refugees, thousands murdered. But hardly seems to be in the public conscience.
It's not to say Israel shouldn't be held accountable, of course it should. That's not anti semtiism. But if there's a disporportionate interest in one situation not explained by the scale of the abuse or suffering or other objective characertisitcs, and where there is clear evidence already of anti semtiic statements, it's not a dififcult jump to figure out the motivation of this singular interest.
In this regard, I always found it intersting that Corbyn was a member of Deir Yassin Remembered, a group to memoralize a massacre which took place in the 1947/8 civil war. Now, it was certainly a tragedy and a war crime. But it's a well-documented massacre. Anyone studying Israeli/Palestinian history will know of it and it's not a forgotten massacre. So why would Corbyn choose Deir Yassin over the many many massacres which have taken place since 1947? Surely he would have his pick of many far worse massacre, far less well documented and, indeed, those committed by the British which might explain why he would want to ensure their rememberance. Say, for example, those in Kenya or Malaysia or India/Pakistan. As it ahppened "Deir Yassin remembered" was shown to be an anti-semitic group (surprise, surprise) which even many Palestinians refused to go near, including the Palestinian Solidarity Committee, but Corbyn (as usual) didn't know, didn't realise, didn't understand. But, aside from his usual ease with which he associates with anti semites, it is very telling that out of all the possible massacres of civilians which have happened in the world, many which truly have been forgotten, Corbyn decided on this one.
www.telegraph.co.uk/news/2017/05/20/jeremy-corbyns-10-year-association-group-denies-holocaust/