Impartiality or viewing figures?

So the Beeb have dropped plans to have a day of saving the planet in the face of critisism of impartiality.

But is that really the case or could it be more to do with the awful viewing figures that Live Earth had?

Update Peter Preston writes in Media Guardian

Of course viewers - 81% of them when the BBC asked - want impartiality, just like motherhood, apple pie and a Euro-vote they'd probably be too busy to cast on the day. But the reality of viewing or voting figures is quite different. A million souls watch Newsnight as it fails to save the planet; about 59.5 million others are asleep, glued to Sky or working. The restraints on coverage, nodding heads from "our Westminster studio", automatically limit the scope of such coverage. Equal time doesn't mean equal interest.