Perhaps. However, when Corbyn was elected leader of the Labour Party in the UK, membership surged and it surged again when he brought out his policy platform which was, compared to what had happened before, quite left-wing, Red. It appeared that the corner had been turned and that people in the UK were fed up with Tories and their privatisation efforts. So, who are we to judge whether or not Corbyn was "too left-wing"? I also thought he was quite brave coming out with the policies he presented to the UK public during the election.
BREXIT obscured the realities of the UK electorate and cut across party lines in a big, big way. There were Tories who were opposed to the deals that the Tory Government brought before Parliament, just as there were Labourites who believed in BREXIT and the deals they were presented with.