All I will say is, things very much changed when RA was removed from the picture. Things I think it was safe to say had soured so badly that other options at the time were the best option.
Rebuilding the IMC was seen as a long term thing, so when you look at the cost of it, it wasn't as bad as you think.
Had the GW deal not transpired as quickly as it did, you would likely be seeing the grain trains moving up and down the IMC right now. There were too many things in place for it not to happen, but the ability for KG not to spend money made it easy up front. Though I am sure the IMC will always remain a wildcard for KG and their ability to move the grain if needed.