I takes a LONG time to get up to headship, especially in secondary! I think the youngest are maybe early 30s? So at the earliest, it would take maybe 10 years.
He reminds me of me a bit when I decided to go into teaching. hated my job, completely demoralised, latched onto the idea of teaching, without really testing out other options.
I was actually offered a sideways move by my company at the time (the company I worked for was great, but the team I was in was awful and the actual work i was doing wasn't me at all). In hindsight, I should at least have tried it out for a year or two - I reckon I would have enjoyed it, and I didn't realise it would have opened lots of other opportunities. However, I was young, idealistic, and was desperate to get away and do something completely different, and had all these idealised notions of 'giving something back' and 'helping people'.
Being older and wiser, I now realise that is all a load of shite and a job's a job. I also didn't realise that once in teaching, it's very, very difficult to get out. I decided to leave teaching a couple of years ago, applied for about 100 jobs and didn't even get a reply (and I'm a scientist, with computer programming skills).
I've now accepted the fact that I'm stuck in teaching. I'm changing my mindset to accept that, rather than fighting to get out.
I really think he needs to look at sideways moves, or the same job with a different company. The organisation you work for makes a massive difference to how you perceive any job.