cost of training
1 - Airlines will "cut corners" whenever (and wherever...) they can.
2 - Airlines have a strong "lobby" with the government to keep requirements (via regs) on the limit. If you have a chance to talk to any FAA POI, he (or she) will tell you that most airlines give poor training to their pilots.
3 - Nice training comes sometimes only by pressure from insurance companies. I've got some nice factory training (in helicopters) not because my boss was nice, but because he would have significant reduction on insurance premiums if he would send all his pilots to factory "refreshment" courses every year, to include power-off touchdown autorotations.
4 - Unfortunately, insurance companies only "think" statistics. More airplanes will have to fall off the sky due to lack off pilot training before they put some pressure on the airlines to raise their "standards".
When I fly as a passenger I look for an airline that has new aircraft flown by old pilots. Unfortunately (again) what I see more is young pilots flying old airplanes...
Rob