I can't speak for Jack but I tried to figure out the "certain" reason from his hints in the other thread. The first place to look was the CEO presentation that he referred to:
http://www.bnsf.com/investors/presentations/pdf/2009jpmorgan.pdf
Slide 15 refers to the increasing volume of imports from Asia since 2000. Between 70%-80% of the imports come in through the West Coast of the US.
From BNSF's website(http://www.bnsf.com/markets/asia/network.html):
"BNSF freight moves over the shortest route from the Pacific Northwest to Chicago, the Northern Transcon, and the shortest route from Southern California to Chicago, the Southern Transcon." (emphasis supplied)
I believe this to be the source of BNSF's sustainable competitive advantage over the other rails for the foreseeable future.
Best,
Ragu