We know that people wouldn’t stop criticising him over Gaza because, a couple of months ago, people were saying ‘All we want is for him to call for a ceasefire’. He did. Now they say ‘All we want is for him to call it a genocide.’ If he does that, they will say ‘All we want is [new thing]’. I’ve proved this point already: I raised a hypothetical way someone might continue to criticise him, and you instantly took it up and agreed that it would be a valid criticism.
Seriously though, please go and do some research so that you can criticise Starmer for his actual position on this. I agree with you that his position is, and has been, the wrong one. Where I disagree with you is 1) on the facts, which I have proved; 2) on the likely consequences of any comments he might make about genocide.