In order for restriction to work it assumes that every practitioner in a given ecosystem will behave similarly, If hospital A does restrict and hospital B does not restrict and they are in the same community and the patients freely move throughout out the community, then the resistant organisms will end up dispersed throughout the community. This does not even take into account individuals coming in from other communities and the veterinary uses of antibiotics which are additional flora disrupters.
Restrictions may work in theory, but they usually lead to unethical practices, where physicians will form 'partnerships' with those colleagues that are able to prescribe. Even if the restriction could be effectively enforced, one must also take into consideration patience adherance to the treatment, the failure of which also results in resistance to antibiotics. I believe that the education of both patients and health care practitioners about correct antibiotic use, and especially the dangers of misuse, would be more effective in the long run.