Corbyn isn't anything like Newsom, he's not a calculating bigot, just a guy completely lacking the political intelligence needed to be a party leader. And so hyper-focused on Gaza that he doesn't see that there's no progressive politics possible in a party full of hardcore religious conservatives.
I don't think he's even supposed to be party leader. The entire point of Your Party seems to be that there isn't one. Which of course just means someone that wants that power will take it.
I do generally applaud Corbyn's commitment to democracy but I agree with you, the point I think he's failed to realise is that without a set of guiding principles, you're just giving a microphone to whoever yells the loudest.