1500 hours in the USA is really to stop low time people working for poor wages on the way to that Legacy airline. US regional airlines had to dramaticallyimprove pay and conditions once the 1500 rule came in.
What bad habits are people learning between 200 and 1500 hours? Getting better at cross wind landing? Getting to fly more complex aircraft? This bad habits tripe was peddled by the integrated schools trying to tell that if you go any other way the airlines won't hire you.