There was lots of analysis just after the election on what Labour would need to do to win the next election given where they are now. The upshot was it would be almost impossible without Scotland and the North for them to recover the lost seats and win the new seats required to gain power at the next election.
In addition, after seeing Labour heartland falls - many more hard core Labour voters who are socially conservative might now feel they have been 'given permission' to vote Tory in future elections.
The best Labour could do next time is to stem their losses and possibly try for the next but one election if they had momentum. This would require a 'New Labour' type renaissance with a Messiah type leader far surpassing Sir Keirs Messiah like qualities combined with continued Tory mis management along the way.
Please don't let it be Tony Blair!
Anyway - time will tell
You know it makes sense! 
