 They're in a state of complete despair because it's almost entirely the fault of the Conservatives. Labour is not very popular. This is an election that the Conservatives have lost rather than that Labour have won. He is a centrist who actually quit the party because he says it's moved too far to the right. It's not only shocking that this transformation might be about to happen in the UK, but the rest of Europe seems to be going the other direction. Like the far right just did really well in France.