Why accept someone for training when they do not prepare for an interview. Training and line flying consists of preparation and commitment. If a person will not study enough (or have a wide enough base of knowledge) to pass the interview tests, then it is a predictor that they will not be successful in either training or completing the probationary period. It does show a bit of restraint to not lower standards when short of pilots. There are still way more people who want to be pilots, than pilot jobs ... thus the downward pressure on wages.