I don't know what your experience has been, but I did not find this to be true at all. I had a very average Step I score (average for US med students, below average for ortho applicants), and it was not mentioned once in any of my interviews. The questions I was asked were the same that everyone else was asked: "tell me about yourself", "tell me about X on your CV", general ethics/current events questions, etc...No one asked me about Alport Syndrome to make sure my basic science knowledge was up to snuff.
My experience has been that board scores are a minimal factor once you get your interview. If you get an interview, then you're qualified for the job as far as grades and board scores are concerned. After that, it's a matter of "who would i want to work with".
The attitude that a 250+ Step I score will put you ahead of everyone with a lower score is dangerous and misinformed. It's exactly this attitude that leads to the guy with a stellar score who gets too cocky, doesn't match and is left wondering "what happened?".