it is still surely the case that the vast majority of teachers go from school to college and then straight back to school with no experience of real life
It certainly was, but not any longer I think. My brother after he graduated (in physics, where teachers have always been in short supply) applied to do teacher training but was turned down by every college to which he applied. The reason given in each case was a lack of life experience.
Now he's been through several jobs, married, started a family - and just qualified as a teacher.
Whilst I don't think I've ever met the arrogance some people claim from hours-building instructors, in my experience they don't have the experience of "real" aviation that the "old and bold" have. Given a choice, if I've got to do some GA instruction (as it happens I have to next week) I always try and ask for somebody that I know to have a lot of real-world flying experience; I always find that I learn more and faster (and argue less with) compared to the hours-builder.
That said, there will always be self-improvers, and since no normal person can afford to clock up 1500 hrs from their own wallet, we've got to accept that instructors of this nature exist - but hope that "old and bold" club CFIs don't just treat them as slave labour, and actually help and encourage their newly qualified AFIs to gain more real flying experience. I think if they do that, absolutely everybody should win - but I've certainly seen schools where the "slave labour" approach is definitely favoured.
G