Why did Labour lose?

http://constitution-unit.com/2015/06/04/the-shy-tory-a-credible-hypothesis-or-mediatic-oversimplification/#more-3990

This seems to be a good demolition of the 'shy-tory' hypothosis, two explanations for teh Tory win:

1) Targetted campaigns not pikced up in national polling.

2) Labour voters didn't turn out.

Put simply, they didn't enthuse their base: so, in the Labour debate about whetehr to tack right or not, this is significant.  With a  difference of two millioon votes between the parties, the obvious way to win is to pursuade one million and one voters to switch sides.  If, though, the problem was enthusing Labour supporters, then tacking left is the option, and two million and one voters might be found. 

Given, though, that would mean promising Labour voters something more meanginful than the same as the othe other team, but with better management, and that appears to be impossible in current conditions (something Syriza seems to be learning hard), then it seems that anything but a rightwards drift is implausible: but that doesn't mean that a Labour Party under Corbyn couldn't win from the left…