It has nothing to do with the skill of the MDs, or even the cleanliness of the hospital in general. That is why most Western nations are in such a pickle with regards to the MR strains. They are quite harmless until the skin is breached. You can sterilize surfaces, but you can't get the air germ free (outside of a handful of isolation cells). Another large portion of infections happens not in the OR, but once the patient has been returned to their room. Catheter sites in particular are a weak point.

One vector for the bacteria to enter a hospital is through visitors. That is one of the reasons why cather sites are so vulnerable. MRSA in particular is carried on the skin, just like its non-MR counterpart. If the freely available antibiotics do indeed breed more MR strains, then that is a reason for concern as a larger portion of the population is expected to carry them.

Unless, of course, MDs are less prone to carpet bomb every sign of infection with antibiotics because the patients already got their own fix. But as you saw, data is hard to come by.