Actually if you bother to have a proper look, without jumping in all guns blazing, you might see some trends in there, particularly London and the SE, often the tory heartland, its a far bigger shift than in other areas of England, especially the north of England, considered a labour heartland in general. Remember London and the SE weren't generally in favour of leaving the EU either, so its not only the UKIP share of the vote that moved.
Its a really interesting graphic on the shift between the two parties, and it doesn't take into account any other party, even in Scotland.
The real reason for the shift was not austerity, or length of time in power, imho, it was an inept decision to have an election in the first place, at a difficult time for the country, followed by an inept campaign, and from the starting position they started with, its a bloody great surprise they made such a mess of it.
I think its unlikely that labour will be able to sustain that position long term in London and the SE, so from a labour point of view in the region, it could be as good as it gets.