I suspect that part of the problem is caused by the commecial liberalisation of the BBC where more and more programmes are actually made by outside companies. An episode of Vicar of Dibley is mentioned, this is produced by the company part owned by Dawn French who is married to Lenny Henry. Both are very commited to aid programmes, so it is not surprising that they produce a programme slanted to support their own views. The BBC has to learn as it clearly has not to excercise more editorial control over it's contractors.
As Auntie is commissioning more and more from private companies, rightly so IMHO, the need for her to be a publicly-funded institution has virtually disappeared. Sponsorship is the only long-term solution, although there is a need to retain those public information services such as the BBC World Service.
It would be interesting to see how many massive contracts like that awarded to Jonathan Ross would see the light of day under a competitively based BBC.