The abundance of pilots in North America is caused due to the carot effect of the large carriers. Brand new licensed pilots are willing to sell their soles in order to build up flite time. Then from a poor paying flite instructor to a poor paying charted pilot job to a poor paying regional pilot job ,always with the hope that some day all this blood ,sweat,and tears will finally pay off. If you finally get the break with the majors,based as much on affrimative action and other politics (UA min pre 911 was 350hrs total time),you hope in 10 to 15 years to make Capt.on a heavy and finally make the big bucks.
If the majors were to sour the reward for this dream job.they would be hard pressed to find enough new pilots in the long term to keep their airplanes flying.
IMO