Instructing has always been a springboard to bigger and better jobs. For a long time now many young (and not so young) people have embarked on instructing as a start to their flying careers. Some have gone on to make it a full time career, far and away the majority have used it as part of the "apprenticeship" to an airline career.
I have some serious reservations about the "Retirement bulge". This term has been kicking around for over 20 years. I have monitored the number of retirements in my company over the last 15 years. The results are that about 5 (on average) pilots retire every year, either due to sickness or age. Looking down the list I can see large groups of pilots that are the same age, however the reality is that this group will (like the others) naturally thin out over the coming years. Again job changes, sickness and early retirement, will modify the so called retirement bulge to a more average figure.
WWW I doubt you have "made enemies" in BA Caledonian or anywhere else. You are as entitled as anyone else to your opinions. As you may know I disagree with what I consider to be the focused issue of " flagging out". I believe we benefit from selling our own services abroad to a much greater extent than those services we import. However that is another subject.
Hopefully the natural laws of supply and demand will apply to any temporary shortage of instructors, and wages will rise as a result. Whatever the result we still need instructors coming into the airlines as First officers. It is a good source of recruitment and always has been.