Thanks for the honest contribution, I know that flying instructors who just did it to build hours to qualify for a CPL in years past caused great resentment both with their colleagues who were in it for the long term and also with their students, some of whom were literally "taken for a ride".
It would appear that the same logic now applies within the airline world where self sponsoring of training allows the airlines to employ an oversupply of pilots and the normal laws of supply and demand ensure that Terms and Conditions decline at the expense of all pilots.
25 years ago, it was harder to borrow the daft sums of money that cadets are now equipping themselves with and therefore the supply of self sponsored cadets was much lower than today and the airlines had to take up the slack by sponsoring and type rating suitable applicants, but even in those days people were willing to take the risk and self sponsor their own training even if a job was not guaranteed. These were the ones who provided proof of concept to the beancounters and paved the way for the mass marketing of the right hand seat that we see today.
It has been going on a lot longer than most people realize.