Teacher-bashing has always had an appeal for politicians. It offers easy headlines and a satisfying sense that things are not what they used to be.
This week, the Commons public accounts committee, under its Conservative chairman, Edward Leigh, produced a report which brought a crop of headlines lambasting the "schools failing one million pupils" and deploring "poor teaching and weak heads".
Mr Leigh's comments that bad schools are ruining the life chances of a million children may be political point-scoring. The committee's report is surely the result of ignorance. Only 54 of 3,500 secondary schools in England are officially classed by Ofsted as failing, and the number in this category has been shrinking. The true figure for the total number of primaries and secondaries causing Ofsted some kind of concern is around 600 rather than the 1,500 claimed by the committee. And where's the evidence that schools are abusing the new "light touch" Ofsted inspections by fibbing about their progress? Ofsted reports are tough on heads who paint a flattering picture of themselves.
But this isn't just an argument about statistics. The committee betrays a lamentable misunderstanding not just of schools, but of the lives of their pupils. It has unthinkingly adopted the view that if a school has poor exam results it must be bad. To teachers in inner-city schools that is a joke.
Nobody claims that the performance of all schools in similar circumstances is the same but it is folly to think that the differences are easily measured.
The absence from the report of any sense of what life is like in the most difficult schools shows a failure of imagination. What about the teachers who help a pupil predicted to get an F at GCSE to get a D? What about the ones who pick up potential truants on their way to school to make sure they arrive? What about those whose pupils were up until midnight and who haven't had breakfast?
Take a trip to Manchester, Birmingham or just up the road to Hackney, Mr Leigh, and see for yourself.