Flaming oil tanks are good for nightly news casts and furthering the anti-energy progressive cause.
Keeping pipelines closed and oil transfered by rail enriches Obama’s friends at Berkshire Hathaway.
When you use a pipeline, you have to make the entire capital investment before you ship one drop. Then you have to amortize, and hope that that the supply point and destination point remain stable, not just for the amortize period, but hopefully a much longer period so that you can make some good money far out into the future. A fifty year old pipeline is a good moneymaker.
OTOH, the rolling pipeline requires a much lower capital investment, and only an incremental capital investment, and can be put into service immediately. And if you need to relocate the rolling pipeline, its very easy to do.
It's easy to solve this problem: raise the flash point and lower the vapor pressure.