"no guarantee that you''ll work for them after you graduate.. they admitted it." ... "grabe"
I am not aware of any airline that will guarantee employment, specially from the start of ab initio training.
Now this is how the cookie crumbles ...
Prior to probationary employment you have to pass physical and medical exams, individual and panel interviews and written tests. Next, you have to pass the airline's aircraft qualification course (simulator and line check rides). Before the six-month probationary period is over the pilot has to undergo a sim check then panel interview again.
Not every Tomas, Ricardo and Horacio can be an airline pilot. Most PAL AvSchool graduates make it, some don't. The airline has a responsibility to the riding public so you fellows have to meet the airline's and the civil authorities' standards.
Even as a regular line pilot there are still mine fields along the way but that is another story.