The Labour Party can make itself electable by ditching Grandpa in a shell suit for starters. The country wants a government that will lead them out of the EU and make this country even more prosperous and successful than it is already - is the man for that job Jeremy Corbyn? Seriously??
It is for the electorate to decide who they want. It is unlikely Theresa May will call a General Election before 2020 so it's all a bit of a fruitless discussion until it is known who will be the leader of the Labour at that time.
Currently Mr Corbyn is leader of the Labour Party elected to that position in accordance with the Labour Party's own rules. Although I see some brief is trying to argue, in court, that Labour's N.E.C can change the rules any time it likes without reference to anyone else, particularly the courts. Nice one.
Mr Corbyn's competence is irrelevant to the process of his election as leader. His removal must be in accordance with the same rules. That's why the P.L.P are having ring twitter but probably more for reasons of it affecting their income potential rather than reasons of altruism or patriotism.
PS I am not a Jeremy Corbyn fan. I am more in favour of the Ottoman Empire style of running a show.