I'm all for improvements in quality and safety. I think the 1500 hour rule is a huge improvement in that one limited area. Of course there are many other areas. The key that no one wants to talk about is training at the airline level because that costs money and its a solution that can't fully manifest by regulatory edict alone.

300 or 1500 or 10,000 hours, the concept of a firehose ground school, 8 sims and a ride is an ancient relic that will take effort to improve on. It was only recently many airlines, even with swept wing jets, stopped teaching the insane pull back at stick shaker because you have to preserve altitude at stall indication +/- 100 ft because of a bizzare misinterpretation of the private pilot maneuvering PTS standards.

Training quality and quantity is going to have to increase at all levels, and pusing a merciless system that purges anyone with any blemishes regardless of context isn't the answer. For every PCL FL410 accident, there's a million hour jet jock from any background out there with excellent creds that balled one up too.

1500 hours is not a one stop fix all. Neither is 10 hours of non reduceable rest with 8 behind the door. But those two things are huge wins in and of themselves.