Just in case there are any student pilots reading this I would like to point out that the start of WWWs last post is a personal opinion.
I have held a flying instructors rating for seventeen years. Like many I now only instruct when the flight time limitations scheme allows.
However, I quit full time instructing after seven years not because I didn't enjoy it, or because I wanted to be an airline pilot, but simply because I had a wife and kids to support.
Since then I been a bush pilot, flown single and multi crew corporate props and jets, and eventually worked my way up to be an airline training captain.
Hopefully, all these things have added to my knowledge of aviation and allowed me to offer more to my ppl students on the rare times that I return to the flying club and get to instruct. And I find the satisfaction of teaching to be as great as it was when I first climbed into the right hand seat of a Cessna 150 with my first ever student.
Many of the people who were instructing full time when I started are still doing so - and if you are learning to fly are worth seeking out.
For many people teaching in the air is a vocation - not simply a job.