Hmm... David Cameron may have screwed up on Energy. But isn't he also right?

When David Cameron said this at PMQs yesterday...

‘We have encouraged people to switch, which is one of the best ways to get energy bills down. I can announce, which I am sure the honourable gentleman will welcome, that we will be legislating so that energy companies have to give the lowest tariff to their customers – something that Labour did not do in 13 years, even though the Leader of the Labour party could have done it because he had the job.’

...he seems to have taken everyone by surprise, not least the Department in Charge of Energy Policy, and the energy companies themselves.

To quote The Spectator...

"Energy companies were also rather astonished and said they were urgently seeking further details of this new policy and how it would affect their business. The implications for those companies’ business models did seem rather large."

Thing is tho - while the announcement may have been a cock up, isn't it also exactly what should happen?

If an energy company is knowingly overcharging a customer for their product, doesn't it say rather a lot about that company, and their respect for the customer. And wouldn't a good company point out to the customer their mistake?

Otherwise, one might assume that the myriad tariffs and deals on offer were designed to confuse their customer, not make things easier for them.

And I'm sure that's not true. So I'm sure the energy companies will be endorsing Cameron's announcement any minute now...

UPDATE

Great quote from Which?

The prime minister must stick to the promise he made in parliament to legislate so energy companies have to give the lowest tariff to their customers. 
Just giving people information on the lowest tariff is not enough when trust is at an all-time low in the industry and switching levels are falling. Which? has been pressing the Government for years to make sure people get a better deal so we must now see these words turned into action.