A We have all heard the old chestnut that many inspectors have never taught the subjects they examine. On ordinary inspections, inspectors do not report on individual subjects. Where they do, as part of Ofsted cross-school surveys, the inspection will involve subject specialists, just as in the old days.
When inspectors did report on subjects, every inspector had to be specifically accredited for any subject they led on the inspection.
I doubt that many inspectors are "in it for the bucks". For those working full-time, the pay rate is probably equivalent to what a senior teacher might expect in a secondary school. It will certainly be less than a headteacher, which is why heads who inspect are more likely to be doing it only occasionally or on short-term secondment. Many part-time inspectors find they are offered work irregularly and so their income is unreliable most of the time.
Typically, they combine inspection work with other work in schools, including as examiners, teacher training or as advisers. I doubt that many are getting rich out of inspecting schools. Most of those involved in inspection are in it because they believe that the process of inspection contributes to school improvement.
The acid test of inspection is whether it can help to make a difference.
Not every inspection will, just as not every teacher is as effective as they can be. However, most should make a difference and if they do not then, yes, the system deserves to be abolished or revamped.
Ofsted can be accused of many things, but conservatism is not one of them.
It is constantly trying to refine and improve the inspection system
Selwyn Ward draws on years of inspection experience. The views expressed here are his own. To ask him a question contact him at firstname.lastname@example.org