Generally yes, but this election was different. The voters should be blamed because the voters should have been smart enough to know what is at stake. The voters should have also known that Trump would not make situation in Gaza better and more than likely things would be worse.
During elections, voters make the decision on who wins or loses so when you have a binary choice and voters decide to either be ignorant or apathetic then yes they should be blamed.
Assuming we're still talking about the Anti-Genocide voters, the Biden Administration and Harris campaign actually drove the stakes of this election way down by committing acts that were worse than anything Trump did in his first term. You cannot make a credible argument about stakes when you're actively aided and abetted a genocide. The voters really had little reason to believe that Trump continuing the genocide would be worse than Biden initiating and overseeing it. And so far, Trump's immoral and criminal demands for the ethnic cleansing of Gaza doesn't represent a markedly worse deviation from Biden's actions to enable Israel to commit genocide to the tune of hundreds of thousands of murdered Palestinians.
To me, the ignorant and apathetic voters were the ones who refused to critically assess the Harris campaign's blunders and demand she switch her gameplan during the election to present an alternative vision that wasn't only appealing to people already deep in the tank for Harris. But those voters were too busy crowing about how leftists and Palestinians were stupid to see their approach was driving the bus off the cliff.
Your hypothetical doesn’t work because Trump was not only saying Biden was soft on Gaza and not supporting Israel enough he said he would finish the job when he becomes President. He said nothing that would make the Arab community think he would be better for the Palestinians than Kamala.
My hypothetical isn't premised on Trump being better on Gaza, it's based on being given two terrible options. Trump is also explicitly courting white supremacists, so I'll ask again, if the Harris campaign decided to drop any policies designed to help the black community and also platform the Klan/Neonazi/White Supremacists in a bid to win over white racists, would you be chastising the black community if her numbers with black voters cratered? Because that's what you're doing to anti-Genocide and Arab voters. Chastising them for not coming out in droves to step over the bodies of Palestinian children and vote for someone who refuses to condemn the genocide of their people.
Additionally Palestine is a foreign issue not a domestic issue. You aren’t making an apples to apples hypothetical so I don’t think it’s a fair to apply it to what actually happened.
Do you believe foreign policy is not a legitimate electoral issue? Were all those anti-war voters motivated to support Kerry in '04 and Obama in '08 not voting on legitimate grounds?