Corbyn went with the majority of the people on the vote, can't hold that against him, even though I have reservations about us leaving the EU - not as depressed as some in here over it as I can see positives from it.
So our glorious leader made sure that the most important issue at the heart of any election is one where there's no differentiation between Labour and the Tories.
As has been pointed out endlessly, the opposition don't just go along with the result of any election or a referendum. That's why they are the opposition and not the government. By definition, the opposition will have lost the last vote and will have policies that didn't get them elected.
Labour (in theory) fought the referendum as a party that supported Europe and our leader (in theory) supported the remain Campaign. The fact that the vote was lost doesn't, or shouldn't change the party's position on Europe. Labour should have maintained it's position as the party of Europe with the obvious advantage that it would give them a clear point of difference to
campaign for in any future election.
Instead Corbyn jumped where he obviously wanted to be anyway and Labour capitulated in the face of the threat of UKIP.