Why do ministers irritate me?

Why is it that whenever I hear a minister on television or radio it makes me irritated. Just listening to Ruth Kelly about the plan to close failing schools after a year if they don't improve. But whenever she was asked she said that if a school has been failing for five or six years then it should be closed. But where does that fit with closing a school after a year?

It seems like they have a pat script and they just say what they want, whether it contains any truth or relevance to the question. Ruth Kelly kept repeating statements like the new academies have worked, some have and some haven't but why keep makeing assertions which are only the partial truth. When challenged with the comments of a head who said that it took five years to turn round a school, she just replied that some schools have done it quicker.

Why are politicians incapable of taking part in a organised simple debate in which there are shades of opinion?