I think the distance from Wall Street has more to do with this result than PSR. BNSF railroad's parent company is a wholly owned subsidiary of Berkshire Hathaway. It's been reported elsewhere that BNSF writes Berkshire Hathaway a check on, I believe, a quarterly basis. It sounds like a situation of as long as the checks keep coming, in B-H pretty much leaves BNSF management to run the railroad as they see fit. BNSF management isn't constantly worried about their short term stock price or what the Wall Street analysts say about them. That said, BNSF Executive Chairman Matt Rose is retiring in April. His replacement may take the railroad in a different direction.
What I find more interesting about this survey is that CSX, CN, and CP, which have all had the benefit of EHH's wisdom, are grouped fairly tightly in the middle of the ranking while NS, which only recently started implementing facets of PSR, is firmly at the bottom.