Just a hypothetical.
Imagine if most of the airlines decided tommorrow that they would not count a single hour of instructing time as a part of their minimum requirements.......what would/could happen??
Anyone new 'up and coming' would instantly dismiss the instructor path as the means to an end.
Instructors would suddenly become very thin on the ground.
The only becoming instructors would be those that were genuinely interested in intructing, and they would probably finally be capable of charging the appropriate rate for their services.
the scarcity and calibre of instructors would mean a mich tighter control on the output of all grades of newly licenced pilots. This would eliminate the 'dime-a-dozen' flying school phenomenon we currently see.
Rates for learning to fly would skyrocket, making it even more of an elitists pursuit.
One problem with this scenario is that instructing qualities are an important component of airline intake, and the airlines would be doing themselves a disservice locking out this pool of applicants. (before we get all the old-school 'charter and bush time is the only way to go' crowd having a shot at me, no I am not, and never have been, an instructor)