In my nieces case, market/peer pressure with the competition having at least a Batchelors, many with Masters becoming increasingly the norm, in order to stand out in a crowded job marketplace felt the PHD was a very necessary qualification edge to have over the others.
Much is the same in teaching - although we struggle for initial applicants, due to the depressed salaries, movement to Leadership is very competitive. These days there is an expectation that you have at least an MA, and the Gov have created a whole raft of NPQ's (8 in total) that again are important just to get you past the initial application and on to an interview short list.
