I wouldn't knock the PPL instructor time too much - 1000 hours teaching people "power, attitude, trim" and trying to mind read their understanding and anticipate their next mistake and how far you can let them try to dig themselves out before intervening are pretty good foundations in basic handling, CRM, workload management and dealing with unusual and sometimes extreme situations quickly that seem to be missing from a lot of cockpits nowdays. That said, the 1500 hours rule is an FAA band aid to look like they are doing something while they do nothing. Improve the quality of training and the problem goes away. 1500 hours of plodding about, reinforcing bad habits after bad training is not going to help anyone.