Ernie Spencer, who has national responsibility for English, told a North Lanarkshire conference last week: "For some teachers the problem is that their heart isn't in it because they know they don't have to do it themselves."
Mr Spencer's comments reinforce those of Douglas Osler, the senior chief inspector, who flagged up a major offensive to drive up writing standards in a foreword to the Standards and Quality report on secondary school English, published in March.
Mr Osler said that weaknesses identified in S1 and S2 "should prompt us to ask more generally if pupils' writing experience is extensive enough across the curriculum as a whole".
A forthcoming HMI report on Improving Writing 5-14, due in September, will reveal that almost half the pupils seen in inspections are not reaching standards of writing appropriate to their stages.
The signs are that teachers will now be "sent back to school" to improve their expertise. A staff development programme is to follow the report, Mr Spencer said, "with a view to ensuring that the good principles of teaching writing are operating in schools throughout the country".
Mr Spencer suggested schools lacked confidence because neither pupils nor teachers have a clear idea of the qualities required in writing, what the writing process is and how to go about teaching it.
He said teachers must realise that effective writing depends on effective thinking, and children should be given more opportunities to think, discuss and talk before starting to write.
"Children grow as users of language through thinking about and discussing things which matter to them," Mr Spencer said. The number of pupils who describe personal experiences in examinations signals "a willingness to write".
But there is little evidence in many schools, especially secondaries, of the coherent approach recommended in 5-14 documents, Mr Spencer said. This was partly because many teachers are either unaware of the documents' existence or do not apply to the Scottish Consultative Council on the Curriculum for the relevant curriculum file.
The Improving Writing report will be based on two key principles - pupils should write about things that matter to them, and children should be made aware that language is something about which they can make choices.
Despite the air of pessimism surrounding the ineffectiveness of writing in schools, Patricia Wilson, primary adviser in North Lanarkshire, reported a major success as a result of the council's writing pack which had raised attainment in every primary class at every level.
Ms Wilson acknowledged the difficulty of encouraging pupils to think but stressed the need to stimulate planning and thinking at an early stage. Raising attainment has to focus on the infant department if a whole-school writing programme is to be effective.
* Boys down their pens
Boys are more likely than girls to suffer from the effects of poor teaching in writing, the conference heard.
"Girls will respond and invent because they will have done more reading. Boys revert to an oral understanding of story," Elaine Millard of Sheffield University said. "If teaching is unstructured, then boys miss out."
Children exposed to structured writing also learn how to learn, not just to deal with the project in hand, and an essential feature of structure was setting targets.
"If children are not set targets, they create their own and this can produce extremely gendered outcomes," Ms Millard said. "Different styles of writing require different targets."